With most of the Premier League teams having passed the halfway mark of their seasons, we now have enough material to assess both individual and collective performances thus far – and for a few players, 2012 will require significant improvements to live up to expectations and reputations.

Per Mertesacker (Arsenal)

The German international arrived at the Emirates from Wolfsburg last summer having been first choice for his country at two World Cups and one European Championship. Given that pedigree, his start to life in the Premier League has been somewhat underwhelming. His lack of pace was always likely to be a concern, but his indecisiveness has cost the Gunners on more than one occasion, and despite his towering six-foot-six frame he has not been the consistently dominant aerial presence one would expect. Recent games have seen an improvement, but Arsenal still look far more secure with their first choice centre-back pairing of Thomas Vermaelen and Laurent Koscielny on the pitch.  

Charles N’Zogbia (Aston Villa)

Identified on this blog as potentially one of the signings of the close season following his £9.5 million move from Wigan, the Frenchman has proven to be a bit of a dud thus far. With his pace, guile, and fearsome left foot, N’Zogbia was expected to be the creative force that made the departures of wingers Stewart Downing and Ashley Young, but has managed just one assist and is yet to find the net in 18 games. In a related story, the Villans have scored just 22 times in 20 matches under new manager Alex McLeish.  

Fernando Torres (Chelsea)

With a full preseason behind him and a starting place to begin the season, the opportunity was there for the £50 million man to rediscover the form that earned him his once-feared reputation. There have been flashes of the old Torres, yet both of his only league goals in 15 appearances – instinctive finishes against Manchester United and Swansea – were subsequently overshadowed in the same game by a glaring miss and a red card respectively. Torres now finds himself in a bit of a catch-22 situation: he possibly needs a more consistent run in the first team to get his confidence back, but his ineffectiveness when he does get on the pitch are preventing that from happening.  

Louis Saha (Everton)

It used to be that Saha’s chronic­ injury problems depressed an otherwise healthy goalscoring rate. Not so in 2011/12 – the French striker has featured in 15 games this season and scored just once, a tally which has been matched by, among others, goalkeeper Tim Howard. As Saha’s lack of sharpness in front of goal continues to exacerbate the problems caused by a lack of creativity in midfield, the decision of manager David Moyes to offload Yakubu to Blackburn looks harder to justify with each passing game.  

Andy Carroll (Liverpool)

With his own eye-watering transfer fee funded (and preceded by a matter of hours) by the sale of Torres to Chelsea, Carroll’s move remains inextricably linked to that of the Spaniard. As with Torres, it was hoped that a summer of preparation with his new team would help him bounce back from a disappointing (and injury-hit) half-season with his new club, but the ex-Newcastle man has only managed to match Torres with a pair of league goals. Part of the problem is that Liverpool’s crossing, presumably a key in getting the best out of Carroll, has been poor, but the 23-year-old has hardly helped matters with his lethargic movement, his clumsy touch, and above all, his wasteful finishing.

Patrice Evra (Manchester United)

The French left-back’s decline had already been set in motion last season, but his performances in this campaign have progressed from disappointing to diabolical. While his pace and energy on the overlap remain key assets for the Red Devils, his defending has generally been woeful, with poor positioning and a tendency to lunge in recklessly his most egregious and persistent failings. United’s struggles at the back have their roots in a number of factors – the absence of Nemanja Vidic, the presence of Jonny Evans, the inexperience of Phil Jones and goalkeeper David de Gea – but Evra’s alarming dip in standards ranks high on the list as well.  

Adel Taarabt (QPR)

There were concerns in some quarters that the mercurial Moroccan, having starred in QPR’s promotion campaign, would be undermined by his individualism and petulance at the highest level. Still, few could have predicted that the 22-year-old attacker would be heading to the Africa Cup of Nations having failed to either score or create a goal in 20 league games, a major problem for a team otherwise starved of inventiveness in the attacking third. With classy Argentine midfielder Alejandro Faurlin ruled out for the rest of the season with an ACL tear, getting the best out of Taarabt will be crucial if incoming Rs manager Mark Hughes is to steer the West Londoners to safety.  

Roger Johnson (Wolves)

Despite a promising start which included two clean sheets in the first three games, the ex-Birmingham centre-back is another who has failed to live up to expectations following a big-money summer transfer. Far from shoring up one of the division’s leakiest defences, Johnson has fitted in seamlessly with the ineptitude around him, with a home defeat to QPR in September marking a particular low point. He even lost his place in the starting lineup to 36-year-old Jody Craddock only for the latter’s injury in the same game to hand him a second chance – one which he must justify with improved performances if Wolves are to avoid another nail-biting relegation scrap come the end of the season.