To resolve his £18 million switch to Barcelona from Liverpool, midfielder Javier Mascherano had to undergo an "exhaustive medical that lasted around five hours."
During this medical at the Hospital de Barcelona, club doctor Ricard Pruna told Barca TV that the Argentine's "cardiovascular [fitness] level is perfect," which can largely be put down to four years spent in England playing in the Premier League.
Wingers and full-backs aside, Javier Mascherano generally plays in a position on the pitch where most running is done, being the box-to-box midfielder that joins in with the attack and yet is back to provide defensive cover when necessary.
Of course an elite level footballer in any league has to have high cardiovascular fitness to play that role, but in the English Premier League, and especially when playing for a title challenging club like Liverpool, a holding midfielder has to have exceptional fitness.
After all, the EPL is well documented as the most physically demanding league in Europe, with teams adopting counter-attacking styles (a la Roy Hodgson's Fulham and now Liverpool), encouraging players to press all over the pitch, and generally making possession of the ball a more valuable thing to have.
And this is exactly why Mascherano can blossom in La Liga, having dealt with the rigours of Premier League life.
In Spain's top-flight, teams tend to pass the ball more often, keep possession deep in their midfield, and venture forward when players have made viable options for a pass.
This means Mascherano will generally have less defensive work to do, meaning when he does have to track a player, make a challenge and protect his defence, especially in the latter stages of the game, fatigue will not take its debilitating effect as much.
In other words, don't expect many deleterious lapses in concentration from El Jefecito, as unlike players like his midfield predecessor Yaya Toure, fatigue shouldn't be an issue in the last ten minutes, meaning the Argentina captain should be on top of his game defensively for 90 minutes, given the proven talent he has with tackling and all other major defensive qualities.
Going forward, Mascherano might also be able to score a few more goals in La Liga than he has done previously in his career, as he'll generally have more kilojoules of energy left in him to make attacking sprints than he would've done in England's all-action top division.
And all of these above statements are backed up by the hardcore statistics.
The average distance covered by a Premier League player in a football match over 90 minutes is 10,344 meters compared to 9,951 meters in La Liga. This is averaged out by strikers and the goalkeeper, so the actual stats for box-to-box midfielders is much higher, especially in the Premier League.
Also, a team of players in a Premier League encounter make an average of 201 sprints per match, compared to just 172 in La Liga.
Players like Mascherano also have to make ground and aerial challenges in the Premier League, with a whole team making an average of 161 ground and 52 aerial challenges per match, compared to just 101 ground and 32 aerial challenges in La Liga.
Also, La Liga lends itself more towards Mascherano than the Premier League at this stage of his career in terms of passes made.
Mascherano will have more opportunities playing for FC Barcelona to claim assists, as players in La Liga make more passes and have a four per cent better pass completion rate than Premier League footballers.
So overall, Javier Mascherano looks set to make less mistakes, score more goals and claim more assists playing for FC Barcelona than he has done with Liverpool.
And if that statement seems absurd, then simply look at the cases of Diego Forlan, Frederic Kanoute, Jose Reyes, Giuseppe Rossi, Cristiano Ronaldo, etc, all of whom have resurrected their careers or become better players technically (Ronaldo and Kanoute).
And in terms in midfield players, the cases of Xabi Alonso, Didier Zokora, Lassana Diarra, etc, prove that Premier League stars can become bigger and better when switched to La Liga.
Simply put, Javier Mascherano will be a success story in Barcelona.