It's a young man's game, supposedly. Yet, for all the pounding athleticism and boundless energy that youth can bring, there is no substitute for experience at the highest level.
The Champions League is the pinnacle of modern club football and it is only at such a standard that the game's greats truly seal their standing within the game. For many, such as the evergreen Ryan Giggs (pictured above), age in no limitation.
In picking an "Over-30 Champions League XI", there are some decisions that need to be made as to criteria for selection.
In order to reward performance this season, this selection rewards those who are a regular starter at a club in the round of 16 aged 30 or over when fixtures began this week.
As the following selection shows, there are many players in their fourth decade still very much at the top of the footballing world.
Given that goalkeeper tends to be a position for the elder statesman of a team, with age and experience beneficial to judgement and organisation, Petr Cech had to beat-off stiff competition to earn inclusion.
The Czech international has been at the top of the European game for a number of years and consistently proves himself to be one of the most reliable goalkeepers around.
He may not pull off the stunning reflex saves of Victor Valdes, or even the Spaniard's distribution skills but when it comes to command of his area, decision-making and reliability, Cech is the undoubted victor.
Having Daniel Alves at right-back has been one of the great luxuries of all recent Barcelona coaches, with the Brazilian having led the way for attacking full-backs for a number of years.
Even on Tuesday night, as the Catalans took on Manchester City, Alves rolled back the years to provide a match-changing contribution from his deep starting position.
Alves may not be seen as the greatest defender by those purists who expect a right-back's primary task to be in negating the opposition's left-winger. However, Alves does just that by pinning them back and ensuring his side's dominance of the right flank.
Chelsea captain John Terry has been resurgent this season, having spent much of the last two years being told that his career as a top-level player was coming to an end.
In tandem with Gary Cahill, though, he has formed a formidable partnership at the heart of the Blues' defence that boasts the best record in the Premier League this campaign.
The Blues will once more find themselves as underdogs in the latter stages of the Champions League, but they have shown before that they thrive on the biggest of occasions. A spirit of defiance against the odds runs through the club and for none more so than their skipper himself.
Having appeared to be on the way out of Real Madrid in the final year of the Jose Mourinho era, Pepe has thrived since the summer arrival of Carlo Ancelotti.
Forming a partnership with Spaniard Sergio Ramos that can only be described as physical, Pepe has enjoyed a new lease of life that has seen him return to the high standards of old this campaign.
Madrid have sensational attacking talent, but they have often looked frail at the back when it has really mattered in recent years. The form of Pepe and Ramos, though, offers encouragement that Ancelotti may have found a means of overcoming those difficulties.
For over a decade, Germany and Bayern star Philipp Lahm has been the perfect example of how a modern full-back should operate at the highest level.
While he is squeezed into our side at left-back, he predominantly plays on the right when at full-back for Bayern. However, he has spent much of the season acting as a defensive midfielder for Pep Guardiola's side.
Lahm is a remarkable player, with his versatility across the defensive and midfield lines unrivalled for the high standard of performances he achieves in all positions. Amazingly, he is still just 30 years old.
Xabi Alonso has been a remarkable player for many years, but his retreat into a deeper-lying role upon joining Real Madrid was the moment that he really took his game to an elite level.
Still an important figure in Real's plans, despite the high-profile capture of suggested replacement Asier Illarramendi last summer, Alonso combines stunning precision in his distribution with intelligence and graft defensively.
His home for the 2014-15 season remains uncertain for the time being, but his priorities currently lie elsewhere as Real search for their long-awaited 10th European title.
A simply magnificent footballer, Xavi has been at the heart of a Barcelona side that changed football over the past six years. As he showed at the Etihad Stadium on Tuesday night, he still remains a terrific player.
Replacing Xavi and the tactical changes that will have to be made to accommodate his eventual retirement are issues that have been high on the agenda at Barcelona for a couple of seasons. For now, though, they still revert to form when the pressure comes on.
The Catalan midfielder will arguably be one of the most underrated footballers of his era, with others consistently taking the headlines while he conducted proceedings. His longevity and success, though, are true reflections of his incredible abilities.
One of the most feared and destructive presences in football, Ivorian Yaya Toure is another to have turned 30 over the past 12 months as the twilight of his career approaches.
At present, though, the mountainous box-to-box midfielder remains an essential cog in the Manchester City wheel and has enjoyed his best goalscoring season to date this year.
He has been on the receiving end of criticism of late for his often lax approach to tracking back and defending. However, there are still very few sides in world football who wouldn't attempt to find a space for Toure if given the chance.
The attacking star of Bayern's all-conquering side of 2013, Franck Ribery is another who has clocked up the big 30 over the past 12 months and looks none the worse for it.
Indeed, while Ribery has always been a considerable talent, the last 18 months have been the best of his career by some distance in terms of making meaningful contributions in pressure situations.
The France winger will hope to make a significant impact in what may be his final World Cup this summer. However, he will first need to take up the mantle for Bayern once more as they attempt to become the first side to retain the Champions League title.
To keep Spain star David Villa out of this selection you have to be an exceptional player and there can be no doubting the credentials of Netherlands star Robin van Persie in that regard.
The former Arsenal man was the star of the show for Manchester United as they claimed a famous 20th league title last campaign and, while inhibited by injury this season, has come up with important goals when required.
Van Persie's success with the Red Devils last season was the first league title of a career that has deserved so much more. A Champions League win looks a distant prospect at present but anything is possible in football.
Zlatan Ibrahimovic scored twice against Bayer Leverkusen on Tuesday night to take his personal tally to an awesome 10 goals in his last five Champions League fixtures.
The Swede is relishing the limelight in Paris and, with PSG looking like genuine outside contenders for the tournament, he may finally have the chance to add the one trophy that has consistently eluded him.
Zlatan has become a cult figure in an age where football has lacked bold personalities. Unlike many who have aspired to such fame, though, his performances on the pitch have matched his personality off it.