As Louis van Gaal prepares to take his fledgling Manchester United side to play Manuel Pellegrini's champions, we take a look at how the two managers stack up against each other.
Louis van Gaal is one of the game's most successful managers—or "trainer-coaches" as he would no doubt say himself. He has won league titles in the Netherlands, Spain and Germany, every country in which he had managed before taking the United job.
He won the Champions League with Ajax in 1995 and came within a penalty shoot-out of retaining the trophy the following season. He took Bayern Munich to the final in 2010, where victory would have earned Bayern the treble.
Although he has had a great deal of success, he does not possess a blemish-free CV. His first stint in charge of the Netherlands was a disaster, as they failed to qualify for the 2002 World Cup. His second spell at Barcelona ended poorly, although it was in that spell that he gave a debut to Andres Iniesta, as partner to Xavi, to whom Van Gaal had given a debut as part of his first tenure.
In an impressive list of achievements, some stand out more than others. Guiding AZ Alkmaar to the Eredivisie title in 2009 was truly remarkable given their relative stature in Dutch football. More recently, his run to third place in the 2014 World Cup in charge of the Netherlands exceeded the expectations of many.
Manuel Pellegrini is two years Van Gaal's junior but began his managerial career a couple of years before the Dutchman. He has found silverware harder to come by than Van Gaal but nonetheless has a slew of impressive managerial feats on his record.
Pellegrini spent 16 years managing in South America, in his native Chile, Ecuador and finally Argentina. He won the Clausura with San Lorenzo and River Plate before heading to Europe. His exploits with Villarreal in Spain mirror Van Gaal's at AZ, with Pellegrini guiding the relative minnows to second place in La Liga in 2008.
He further cemented his reputation by guiding them to the quarter-finals of the Champions League in the subsequent season.
He guided Real Madrid to a then-club-record haul of 96 La Liga points, but Barcelona's dominance was such that it was not enough.
After a spell at Malaga, Pellegrini got the chance to prove his worth at City and finally broke his European silverware duck, winning the Premier League in his first season in charge.
For their third-place finish at the World Cup, the Netherlands owed an enormous amount to Van Gaal's tactical adaptability. In their second-round clash against Mexico, for example, his switch from 3-5-2 to 4-3-3 predicated the Oranje's comeback.
His use of 3-5-2 in the first place was an innovative solution to the problem caused by the injury to Kevin Strootman, a vital player in Van Gaal's Netherlands side.
At Ajax and Barcelona, Van Gaal played 4-3-3. At AZ, he switched to 4-4-2 after a run of poor results, and things improved immediately. At Bayern Munich, he implemented 4-2-3-1. Back in charge of the Netherlands, ahead of Strootman's injury, he played 4-3-3 again.
At United, he is still experimenting with tactics. He has lined United up playing 3-4-1-2 and switched to 4-3-3 and 4-4-2. He then began to start with a diamond midfield. Then, faced with injuries to key players in that diamond, he moved to 4-5-1/4-3-3 against West Bromwich Albion and Chelsea.
It is clear that tactical flexibility is part of Van Gaal's repertoire. The lack of stability caused by this does appear to be having some detrimental effects on United's fluidity, but it is early days for his time at an injury-hit United, and the Dutchman is in a phase of experimentation.
Pellegrini, on the other hand, has been criticised for his lack of tactical variety. His team's distinct 4-2-2-2 has, of course, yielded success, but The Times football writer James Ducker is not the only voice suggesting the Chilean needs to develop a plan B.
It's getting to stage where Pellegrini will have to tweak his system more for certain matches. Opponents are learning how to play them— James Ducker (@DuckerTheTimes) October 26, 2014
Pellegrini's system does allow for plenty of rotation, as Bleacher Report's Rob Pollard discusses here. City and United have very different needs in this area, as Pellegrini balances European and domestic competition and the needs of a squad with more obvious strength in depth.
Most of Van Gaal's rotation this season has come as a result of injury or suspension to players who would have otherwise played, with the exception of his decision to sacrifice Juan Mata in the interests of playing Robin van Persie, Wayne Rooney and Radamel Falcao in the same side.
Van Gaal has a profoundly mixed reputation in this area. Those players with whom he has clashed tend to carry the scars. Brazil international Giovanni, who played for Van Gaal at Barcelona, said of him, per Sky Sports:
Van Gaal is the Hitler of the Brazilian players, is arrogant, proud and has a problem. He has no idea of football. His type is sick, he's crazy.
Lucio, another Brazilian, said Van Gaal hurt him "more than anyone else in football" after the manager sold him when in charge of Bayern Munich, again per Sky Sports.
Zlatan Ibrahimovic described Van Gaal, per the Daily Mirror, as "a dictator, with no sense of humour."
On the other hand, some players have loved him, often those whose career Van Gaal has been instrumental in shaping. Thomas Muller told Sports Bild (h/t Goal.com):
It's not a secret that Louis van Gaal and I have a relationship that goes a bit further than a normal trainer-coach relationship.
Patrick Kluivert was involved in Van Gaal's Netherlands coaching setup and came through as a player under him at Ajax. He has been fulsome in his praise, saying, per Sky Sports:
He would be absolutely the first pick of any club, especially top teams everywhere in the world. He likes to let young players make their debut if ready for it.
Xavi said of Van Gaal, per Marca: "I owe Louis a lot. He was great with me and trusted in me."
Pellegrini has been popular at Manchester City, and his players have been happy to praise him for his man management. Yaya Toure cited the difference the Chilean had made as crucial to their title-winning season, per the Mike Keegan of the Manchester Evening News.
"All our confidence comes from the manager," Toure said.
The atmosphere, the manager and the confidence, that’s the difference between last year and this year.
He [Pellegrini] trusts the players, the philosophy is about all the quality we have in this team. That’s the big difference.
In Sergio Aguero's recent book, serialised in the Daily Mirror, Aguero wrote of Pellegrini:
I knew Manuel Pellegrini from my time in Spain. I'd only heard good things about him, that he was someone who instilled the confidence in his players to go out and play good, attacking football.
Over the past year or so I've discovered he will never give up or allow his players to give up no matter what the situation is.
They have a very different public persona and very different styles. Van Gaal has a larger-than-life quality, whereas Pellegrini is more reserved. However, it is clear that when working with players, they are capable of inspiring belief and support.
In truth, the relative merits of the two managers will be far from the only determining factor on Sunday. Pellegrini took over a project well underway when he arrived at City and is working under a solid hierarchy with a clear transfer strategy.
Van Gaal arrived at a club devoid of confidence and has begun an enormous rebuilding task. The dugout battle will have a bigger impact once Van Gaal has been in post a little longer.
For now, United are cast as underdogs, and getting one over on Pellegrini will require every ounce of Van Gaal's hard-won nous.