It is the time of year when attention turns towards football's end-of-season awards. While there are Oscar equivalents to reward the worthy, the game could benefit from its version of Razzies, honouring the unsuccessful. And in that spirit, here are the nominations for the worst signing of the season.

10. Gabriel Obertan (Manchester United, £3 million)

He can run rather quickly and likes a stepover, but there the similarities to Cristiano Ronaldo end. Admittedly, Antonio Valencia was a more direct replacement for the Portuguese than the untried Frenchman and there is still time for the 21-year-old to make an impact but, before reappearing at the end of the Manchester derby, Obertan had disappeared off the radar, suggesting he is near the back of a long queue of wingers.

9. Diego Arismendi (Stoke, £2.5 million)

He came, he saw, he vanished without trace. Diego Arismendi was supposed to add another dimension to the Stoke midfield. Instead, he has barely figured in it. The Uruguayan has only played in two Carling Cup games: he was hauled off at half-time in the first, but completed the second, a 4-0 defeat to Portsmouth. He has since been loaned to Brighton, managed by his compatriot Gus Poyet, but the fact that half of his four appearances in League One have been as a replacement indicates he has endured difficulties there, too.

8. Tal Ben Haim (Portsmouth, undisclosed)

Since excelling at Bolton, Tal Ben Haim has made an unfortunate habit of appearing on such lists. Moves to Chelsea, Manchester City and Sunderland can hardly be called successes. Nor, following his August switch from Eastlands, can his stint at Portsmouth be judged favourably. For the first half of the campaign, he was unable to displace Marc Wilson and Younes Kaboul from the central defensive positions. Subsequent appearances have been underwhelming and, with the fire sale at Fratton Park set to continue, Pompey may find themselves counting the cost of giving Ben Haim what is thought to be a lucrative four-year contract.

7. Manuel da Costa (West Ham, swap)

There is such a thing as cause and effect in trading. West Ham made Savio Nsereko their record signing last season. When he underachieved, the forward was exchanged for Fiorentina centre back Manuel da Costa. Around the same time, West Ham sold James Collins to Aston Villa, where the Welshman has proved himself to be one of the division's most dependable defenders. The same cannot be said for Da Costa: West Ham have conceded 18 goals in the nine games he has started.

6. Mike Williamson (Portsmouth, £3 million)

For those wondering why Portsmouth plunged into administration, a glance at Mike Williamson's recent career should offer an insight. Signed for £3 million and sold five months later for £1 million, the former Watford defender never made an appearance for Pompey before being transferred to Newcastle. Even before wages, agents' fees and a signing-on fee are taken into account, that is a loss of £2 million with no discernible benefit to Portsmouth. It is hardly his fault but, from a financial perspective, he was a terrible buy.

5. Benni McCarthy (West Ham, £2.25 million)

It is not a particularly enjoyable admission to make, but perhaps Sam Allardyce was right. The Blackburn manager questioned Benni McCarthy's fitness and work-rate before selling him. Since then, a fee of £2.25 million and a lucrative two-and-a-half year deal has bought West Ham a grand total of 155 minutes' ineffective football, no goals and no points. All five games in which he has appeared have resulted in defeat. McCarthy may be (just) slimmer than Mido, but he is a much bigger investment.

4. Roque Santa Cruz (Manchester City, £18 million)

Sometimes the phrase "more money than sense" does apply. There was only one serious bidder for Roque Santa Cruz and his lengthy injury record should have been used to drive the price down: instead, Manchester City paid £18 million to acquire a man who has spent much of the season either on the bench or the treatment table. Santa Cruz has only started five league games and, in one, contrived to injure himself in innocuous fashion in the opening minutes. Compared to his paltry return of three goals, Emmanuel Adebayor and, in particular, Carlos Tevez are delivering value for money.

3. Jason Scotland (Wigan, £2 million)

Sometimes scouting systems fail. On other occasions, perhaps would-be buyers know their targets too well, the memories of their triumphs serving to obscure their flaws. Jason Scotland spent two years scoring goals at Swansea for Roberto Martinez and, when the Spaniard moved to Wigan, the striker followed suit. A regular scorer in League One and the Championship, the Trinidad & Tobago forward may rank as the Premier League's least prolific forward: 30 games have brought a solitary strike. And even that came in a defeat.

2. Kolo Toure & Joleon Lescott (Manchester City, £14 million & £22 million)

With money no object, Mark Hughes went shopping for defenders. And while John Terry eventually opted to stay at Chelsea, the former Manchester City manager had the opportunity to assemble an enviable back four. He produced a ridiculed one. Kolo Toure fared rather worse than his cheaper replacement at Arsenal, Thomas Vermaelen, while Joleon Lescott appeared, especially in the first half of the season, unnerved by the price tag and a rather lesser player than the man who excelled for Everton. And as Roberto Mancini has discovered, City's most reliable centre back is one who was already at the club: Vincent Kompany.

1. Alberto Aquilani (Liverpool, £20 million)

Yes, he has been unfortunate with injuries and, yes, as Rafa Benitez was fond of saying, Aquilani was signed for the five-year duration of his contract rather than a few months, but it has been a dismal start to life at Liverpool. His debut was delayed, his impact has been negligible and even his manager appears unconvinced. As Anfield appearances against Fulham and Portsmouth have shown, Aquilani has ability in abundance, but the solidity of Lucas Leiva tends to earn the Brazilian a place for the more demanding games. Replacing Xabi Alonso was never going to be easy, but Aquilani's troubled time at Anfield makes it far harder than envisaged. He may be unlucky, but the size of his fee and the size of the task made it imperative the Italian flourished. It is an understatement to say he has not.