He's a 'Bright Young Manager', which is meant as a huge compliment, and he's also affable and approachable. It's actually quite difficult to dislike Roberto Martinez...
WhoScored.com look at five sides who, after the opening four matches of the season, seem to have made tactical alterations to their style over the summer...
Defenders, midfielders and forwards will follow...
David de Gea
Despite his obvious potential, doubts remain over De Gea and an error against Fulham in August saw the 22-year-old lose the number one spot to Anders Lindegaard for four Premier League matches, including the trip to Anfield. "I think young David made a mistake," said Sir Alex Ferguson after the Fulham game. "With the form he's been in, he's been making some fantastic saves but one error like that could have cost us the game."
The Manchester United manager continued to rotate his keepers until the start of December, but since starting back-to-back games against Manchester City and Sunderland, De Gea has retained his place in the side, starting every match apart from the FA Cup replay against West Ham.
United fans have staunchly defended De Gea following undue media criticism of the young Spaniard early into his first season at Old Trafford, but there are certainly areas of his game that require improvement, which Ferguson has also acknowledged. "I haven't seen the (Liverpool) goal again but it looked a bit soft," said the manager following United's win over their rivals in January. "Once again the keeper has parried one out and nobody is following in the rebound."
De Gea did well to get down to Steven Gerrard's low drive, but it wasn't the first time the keeper has failed to push the ball to safety in recent weeks, and Ferguson has clearly noted similar errors against Man City and Newcastle. It's a problem the manager didn't have to consider during Edwin van der Sar's time at the club.
There have been signs that De Gea is learning though - especially in terms of his command of the penalty area - but United will have to accept the occasional heart-in-mouth moment as the 22-year-old continues his development. This clip, which shows the keeper failing to deal with a cross before superbly clawing the ball away from goal against Newcastle, sums up De Gea's strengths and weaknesses and Ferguson must hope that the 'one costly error' he fears doesn't come in United's Champions League clash with Real Madrid.
Hart's performances this season have polarised opinion, with some (namely the ITV panel) claiming the keeper is the best in the world, and others suggesting he isn't even in the top ten.
The truth is that Hart is within spitting distance of the top group of goalkeepers (perhaps more so than ever considering Iker Casillas's form this season) and his performance in Manchester City's 1-1 draw with Borussia Dortmund underlined his fantastic ability.
But Hart is far from the finished article and as Roy Keane suggested following the keeper's costly error in England's 1-1 draw with Poland in October, the 25-year-old has perhaps started to believe his own hype.
Keane was concerned that Hart's "cockiness" would harm his progress this year and the keeper's poor performance in England's friendly defeat to Sweden suggests he has allowed complacency to creep into his game. That his save percentage has fallen by ten per cent from last season is quite a telling indictment of a drop in form.
Considering his age and impressive career thus far, there is potential for Hart to one day establish himself as the best in his position. But at this stage, that aim shouldn't be a pressing concern and Hart should focus on finding the consistency that played a key part in Man City's maiden Premier League title victory.
Although Reina has always been prone to the odd glaring error (and unfortunate beach ball mishap) the Spaniard's performances this season have suggested a gradual decline in his ability and there has been plenty of speculation linking Liverpool with a move for a new number one in the summer. Borussia Moenchengladbach's promising young Germany international Marc-André ter Stegen is one of several reported targets, with Ali Al-Habsi (more on him later) also linked with a move to Anfield.
Reina is still highly regarded by Liverpool fans, unsurprisingly, but the keeper started the season with an embarrassing mistake in the Reds' 1-1 draw with Hearts in the Europa League and has continued to look out-of-sorts.
"Pepe's a good guy and what's important is that you reflect on the mistake and you use it as a lever to move on," said Brendan Rodgers after the Hearts match. But just three days later Reina parried Santi Cazorla's effort into his own net in Liverpool's 2-0 defeat to Arsenal.
That Reina has achieved seven clean sheets in 18 Premier League matches thus far shows that his form is mixed, rather than consistently below par, but a saves-to-shots ratio of just 64.7% (compared to 69% last season) paints a broader picture of his problems.
There have been mitigating factors - such as a nagging hamstring injury in October - while Reina has also had to adapt to Rodgers' intention for the Reds to build gradually from the back. The keeper is not the only Liverpool player to make errors this season - one wonders if the Reds' progress would have panned out any differently had Martin Skrtel's back-pass not deprived them of an impressive victory over Man City in August - but of the experienced members of the squad, his form has been the most worrying. A summer exit may be on the cards.
Szczesny's breakthrough in 2010/11 was heralded as an end to Arsenal's goalkeeping problems, but several erratic displays last season raised concerns over the keeper. Despite a third place finish, Arsenal's 'goals against' record of 49 marked their worst total since 1983/84, with the unpredictable Szczesny seen as a key factor in the team's porous back line.
That statistic wasn't the most startling from Szczesny's first full season as number one, though, with the Pole possessing a save percentage of just 63.2% - the third lowest of all regular Premier League keepers behind relegated duo Paul Robinson and Jussi Jaaskelainen. And to compound a difficult campaign, the 22-year-old was sent off in his only match for Poland at Euro 2012 as the hosts crashed out in the group stage.
Szczesny's steep learning curve has perhaps stood him in good stead for a career behind the likes of error-prone duo Laurent Koscielny and Thomas Vermaelen and since returning from injury he has shown signs of real improvement.
The Pole's saves-to-shots ratio has shot up by ten per cent and it would also appear that he is taking fewer risks as his anticipation of danger develops. Arsene Wenger will be pleased that Szczesny is finally maturing and the manager is likely to keep faith in the keeper rather than look for alternatives, as has been reported.
Although Al-Habsi has previously been tipped for a move to a 'big' club - with Liverpool apparently among the suitors - the keeper is currently enduring his worst season to date at Wigan, with several costly errors undermining his reputation.
The Oman international's error in the Latics' defeat to Man City presented Mario Balotelli with a simple chance to grab his only Premier League goal of the campaign, and Al-Habsi also had Jordi Gomez to thank after the playmaker spared his blushes following an embarrassing mistake against Reading.
Now 31, Al-Habsi no longer has the excuses available to De Gea, Szczesny and Hart (to an extent) and if he hopes to earn a bigger challenge he will need to rekindle the form he displayed in Wigan's incredible survival run last season. It doesn't help that he's playing behind the third-worst defence in the league.
Matt Stanger - he's on the Twitter.