12 World Football Injuries Which Have Had the Biggest Impact in 2014/15 Season

It's unfortunate but true—injuries are as much a part of football as goalposts, shin pads and dribbling, and not a season will go by without teams suffering due to the amount of players they have on the treatment table.

In this slideshow, we look back at the 2014/15 campaign and examine whose injuries had the biggest impact on their respective sides. Factors taken into consideration include club form and results without the players in question.

The slides are ranked according to the players' importance to their club and the effects their absences have had over the course of the season. 

This is not an exhaustive list, so please feel free to add your own suggestions below.

12. Michael Carrick, Manchester United

Rui Vieira/Associated Press

A key influence in midfield, you have to wonder if Manchester United would be pressing Chelsea a little harder in the Premier League if Michael Carrick had been available all season.

The 33-year-old took no part in the first nine games of the current campaign, a period in which United won on just three occasions and conceded 13 goals.

Carrick made a substitute appearance against Manchester City on November 2 and was back starting six days later, facing Crystal Palace.

Upon his return, Louis van Gaal's side went on a 10-match unbeaten run before a defeat to Southampton on January 11.

Since then, Carrick has spent another six games on the sidelines and has played in a further six. Manchester United have won every single match in which he has appeared, winning just three without him.

As The Independent's Mark Critchley recently wrote, following United's most recent outing—a 1-0 loss to Chelsea: "[Carrick]'s found a red shirt 89 per cent of the time since returning from injury and regularly finds himself at the top of the pass completion charts come the final whistle."

Currently facing another battle to be fit for United's fixture against Everton, as reported by Mark Ogden in The Telegraph, Carrick's fitness could continue to impact where Van Gaal's side finish this season.

11. Alan Dzagoev, CSKA Moscow

Denis Tyrin/Associated Press

Alan Dzagoev, pictured left.

Russia international Alan Dzagoev has been out of action for CSKA Moscow for their last four games in the Russian Premier League.

It is no coincidence that the division's reigning champions have not won a game in this time.

In the three games previous, during which time CSKA extended their winning streak to six, Dzagoev scored twice and added an assist.

Despite a tendency toward picking up suspensions, the 24-year-old is easily one of his team's most pivotal players, and the versatile midfielder's absence through injury may prove to be telling as the Russian season winds up.

With just six games to go, recent results have seen Leonid Slutsky's side lose sight of leaders Zenit Saint Petersburg, who are in first place with 56 points. CSKA are currently on 44. 

Last term, Dzagoev appeared in 18 Premier League games, and he was on the losing side just twice on the way to winning a second consecutive league title.

10. Marcos Lopes, Lille

Alastair Grant/Associated Press

It's been a disappointing campaign for Lille, who currently sit eighth in Ligue 1—15 points behind leaders Lyon.

Rene Girard's side have finished outside the top three once in the last three seasons, and as recently as 2010/11, they were champions of France.

The summer departure of Salomon Kalou, Lille's top scorer last term, and attacking midfielder Dimitri Payet in 2013 left Les Dogues with a dearth of attacking talent, and most of the club's hopes were pinned on loanee Divock Origi.

The arrival of Marcos Lopes on a short-term deal from Manchester City was meant to change all that.

An exciting young talent, the Portugal under-21 international featured in the first eight games of Lille's season, in which they were beaten just once. Injury struck during the winter months and Lopes was forced onto the sidelines—clocking up just 43 minutes of football between October 5 and January 17.

Out for a further three games, the 19-year-old has played in 10 fixtures since, scoring two and assisting two and being described by a L'Equipe journalist (h/t Adam Crafton in the Daily Mail) as "the club's most important player. Amazing, for 19."

As Crafton writes: "After overcoming the hamstring problems that hindered the first half of his campaign, he has dazzled the French with his silky passing and eye for goal, emerging as one of Europe's most prolific teenagers."

If Lille had Lopes available all term, their league position may be a lot better than it is now. According to Simon Jones in the Daily Mail, Girard would like to keep Lopes at Stade Pierre-Mauroy for one more season after his current loan deal runs out.

9. Siem de Jong, Newcastle United

Peter Dejong/Associated Press

Bought by Newcastle United for £6 million in the summer and subsequently appointed vice-captain by then-Magpies manager Alan Pardew, it looked like this would be a huge debut Premier League season for Siem de Jong.

"Siem will give us intelligence in the final third and create goalscoring situations," said Pardew, reported by BBC Sport. "It is a big signing for this club."

Unfortunately for the Magpies and the player himself, De Jong tore a thigh muscle after playing just 99 minutes of top-flight football for the club—draws against Aston Villa and Crystal Palace.

On the road to recovery from his initial injury, De Jong then suffered a collapsed lung in February, which required further surgery.

Meanwhile, Newcastle have been going through a torrid time—struggling for goals, losing Pardew to Crystal Palace and, correct at the time of writing, recording just one win in their last 10 games.

It's difficult to know for sure, but De Jong's inclusion in the Newcastle squad could have made a big difference, so his absence should not be underestimated.

The attacking midfielder is a Netherlands international and was club captain at Ajax, where he won four consecutive Eredivisie titles.

8. Lorenzo Insigne, Napoli

Fabrizio Giovannozzi/Associated Press

Lorenzo Insigne ruptured the anterior cruciate ligament in his right knee on November 9, when Napoli took on Fiorentina at the Stadio Artemio Franchi.

It was thought the 23-year-old would be out for the rest of the season, reported by Football Italia. 

Insigne was on the sidelines for a lengthy spell, missing out on 17 Serie A games and six in the Europa League. Replaced by Belgium international Dries Mertens, Rafael Benitez was fortunate to have another clever, quick winger eager to be given extended playing time.

However, Mertens—for all his talents—did not start the season in blistering form, and after suffering a concussion against Cagliari one week after Insigne's ACL tear, he found himself back on the bench, with Jonathan de Guzman often filling in on the left.

When Insigne—a Naples born player and an idol to the Partenopei support—was out, it came as no surprise to see Napoli go on a run of four games without a win.

It was a far cry from previous weeks, in which Napoli had won 6-2 against Hellas Verona and had beaten Roma and Fiorentina 2-0 and 1-0 respectively—a large part of that being down to Insigne's growing influence on his team.

Napoli should have third place sewn up in Serie A, yet they currently sit in fourth, five points behind Lazio and Roma in second and third. Insigne is already back from injury, but one nagging thought remains: Had he been available all season, and continued to flourish, would things be different for Benitez and Co.?

7. Andy Carroll, West Ham United

Matt Dunham/Associated Press

Andy Carroll began the season on the sidelines at West Ham United, and when the curtain comes down on the 2014/15 season, it's likely that he will be there again.

The 26-year-old's career to date has been pockmarked by injuries, and when he suffered medial ligament damage during a 0-0 draw with Southampton in February, it made for wretched, although unsurprising, news.

Sam Allardyce's side, buoyed by the arrivals of Diafra Sakho, Enner Valencia and Alex Song, made a remarkable start to the season, prior to Carroll's return, with wins against the likes of Liverpool and Manchester City in the bag.

And when the striker returned on November 8, he served only to improve his club's impressive performances in the top flight.

"In terms of his playing style, Carroll looks as if he represents the spirit of a striking ideal from years gone by, and Allardyce was at pains to point out that the values he represents should not be overlooked in modern football," wrote the Guardian's Amy Lawrence on December 7, with the Hammers third in the table.

By Christmas, Carroll had scored three and assisted one with his team on the end of just one defeat in seven games.

In the Mirror, Steve Stammers wrote: "There is no question, no debate that a fit and firing Andy Carroll will have a huge part to play if West Ham are to maintain their pre-Christmas surge in the Premier League."

With Carroll a constant threat and playing in a system designed to play to his strengths, more solid performances were to follow, with the striker adding a further two goals to his tally against Swansea City and Hull City. 

However, after injury hit on February 11, the Hammers' form soon took a nosedive. With Valencia also out through injury, West Ham have won on just one occasion in their last eight games, reiterating Carroll's importance to the team.

6. Laurent Koscielny, Arsenal

Associated Press

Arsenal have been ravaged by injury this season, with a number of first-team players forced onto the sidelines for extended periods.

By Christmas Day, Arsenal had won just seven league games, compared to 11 at the same stage last season and, as reported by the Guardian's David Hytner:

"

Arsene Wenger has rejected the allegation that Arsenal have gone backwards in the Premier League this season, arguing that the club's horrendous injury problems have simply been too much.

Arsenal were level on 36 points with the leaders Liverpool on Christmas Day last season whereas this time out—also after 17 matches—they have 27 points and sit in sixth place. They trail the leaders, Chelsea, by 15 points.

"

The impact of these injuries cannot be denied, with key players such as Olivier Giroud, Theo Walcott, Jack Wilshere, Aaron Ramsey and Mesut Ozil all missing out on large chunks of the season.

However, it was Arsenal's back line that suffered the most in the early stages of 2014/15.

Having failed to replace the Barcelona-bound Thomas Vermaelen over the summer and with right-back Mathieu Debuchy suffering a long-term injury after just four games, Arsenal lost one of their only true centre-backs in Laurent Koscielny after seven fixtures.

Wenger was forced to construct a makeshift defence on a number of occasions—playing full-backs Nacho Monreal and Calum Chambers in central defence, with Per Mertesacker his only fit and recognised centre half.

The Gunners drew five of their first eight games (two of which they dropped points from winning positions) and lost games on the road to Swansea City, Stoke City and Southampton.

Had Arsenal had a robust defence featuring a healthy Koscielny, they could have been challenging Chelsea for the title as we speak.

5. Riccardo Montolivo, AC Milan

Sang Tan/Associated Press

Italy international Riccardo Montolivo was forced to miss the World Cup after fracturing his tibia in a friendly with the Republic of Ireland.

The AC Milan midfielder also missed the first 12 games of the 2014/15 Serie A season—with the Rossoneri's seemingly endless struggles continuing, as they recorded just four wins in that time.

Back on the pitch on November 30, the 30-year-old featured in a run of eight games in Serie A before falling to injury in February. Since then, Montolivo has appeared in just two games—forced back onto the treatment table due to a hamstring problem. 

As one of the best and most dependable midfielders in the Milan squad, Montolivo is sorely missed at San Siro, where Nigel de Jong has also been ruled out through injury on several occasions this season.

Both creative and defensively solid, Montolivo is Milan's club captain, and his leadership, composure and range of passing are a vital part of Filippo Inzaghi's side.

4. Kevin Strootman, Roma

Riccardo De Luca/Associated Press

Roma have morphed from a team with a genuine chance of winning the Scudetto to a side some 15 points behind leaders Juventus—oh how they have needed Kevin Strootman this season. 

The 25-year-old, who has had terrible luck with knee injuries over the last couple of campaigns, has had just six outings in Serie A this term.

Miralem Pjanic has also suffered through knee problems, relayed by Forza Italian Football, Daniele De Rossi has played in just six of his side's last 13 games and Seydou Keita has missed out through injury and suspension after returning from the Africa Cup of Nations. All this in just central midfield!

Rudi Garcia's side, who have recorded just four league wins in 2015, are like a different team to the one that started the campaign with such aplomb. Injuries—including long layoffs for Maicon and Leandro Castan—have rocked the side, the departures of Mehdi Benatia, Mattia Destro (loan) and Tin Jedvaj (loan) have not helped. The loss of Keita and Gervinho to the Africa Cup of Nations further damaged their cause.

Strootman, who has racked up 31 Serie A games between 2013/14 and 2014/15 and been on the losing side just twice in that time, would have been a crucial player for Roma this season.

3. Luka Modric, Real Madrid

Daniel Ochoa de Olza/Associated Press

Luka Modric picked up a hamstring injury in November that would see him miss out on 15 games in La Liga.

During his absence, Los Blancos were beaten 2-1 by Valencia, 4-0 by Atletico Madrid and 1-0 by Athletic Bilbao. In the Copa del Rey, they were beaten 2-0 by Atleti and knocked out after a 2-2 draw in the second leg.

Quite a shock for a team who had been on a 13-game winning streak up to the point of the Croatian's injury.

Injuries to Pepe, Sergio Ramos and James Rodriguez did not help matters while Modric was on the sidelines, and though Isco deputised admirably in midfield during his absence, Modric's calming presence was and is nigh on impossible to replace.

Modric was back in action on March 15, and Madrid have lost just once in La Liga since.

With just six league games remaining and a crucial Champions League quarter-final second-leg tie against Atletico Madrid fast approaching, Modric is once again on the treatment table, this time with a knee injury, as seen on ESPN FC.

With the business end of the season already upon us, we'll see exactly how crucial Modric's latest injury will prove to be.

2. Daniel Sturridge, Liverpool

Matt Dunham/Associated Press

Daniel Sturridge has spent most of the 2014/15 season watching from the stands, as Liverpool have failed to recapture the form that saw them finish second in the Premier League last term.

The 25-year-old was needed more than ever by his team for the current campaign, following Luis Suarez's summer departure to Barcelona.

However, a chronic thigh problem has kept him in the hands of the Reds' doctors for all but 12 league games. Sturridge did not play a single minute of Champions League football for Brendan Rodgers' side, who crashed out of the competition in the group stage with just one win from their six games.

Sturridge ended last season with 21 goals in 29 games in the English top flight. This term, he has bagged just four in 12 appearances.

1. Marco Reus, Borussia Dortmund

Frank Augstein/Associated Press

Borussia Dortmund's descent into the lower reaches of the Bundesliga shocked many this season. By December, Jurgen Klopp's side were bottom of the table.

With an injury list as long as the Ruhr, BVB were missing a number of key players as the campaign kicked off, with Mats Hummels, Marcel Schmelzer, Ilkay Gundogan and Jakub Blaszczykowski among those on the sidelines.

However, spells without Marco Reus' creativity have hit the team hard during 2014/15.

The 25-year-old captained Dortmund on the opening day of the season (a 2-0 defeat against Bayer Leverkusen) and went 87 minutes in the following fixture (a 3-2 win against Augsburg), in which he scored and registered an assist.

By the third game, Reus was out of action with a ruptured ankle ligament. In the following five games, Dortmund won just once.

The Germany international was back by October 18, by which time Dortmund were suffering domestically, having won just two fixtures all season. Despite notching two more goals and one assist, Reus' team continued to slump as the winter break approached. The winger tore his ankle ligaments again on November 22, ruling him out until January.

With Reus back in the lineup on January 31, Dortmund went on a run of 10 games suffering just two defeats, winning five and drawing three. In this period, the Dortmund-born player scored four and assisted three.

It's there for all to see: Klopp's team are simply better with Reus in the side.

With Dortmund now back in the upper half of the table, Reus has missed his side's last two Bundesliga outings due to a groin problem, as seen on the club's official website.

All player information and stats comes from Transfermarkt and ESPN FC unless stated otherwise.