Sheffield United will feel all the more aggrieved that Carlos Tévez helped to ensure that West Ham United avoided relegation yesterday as the Barclays Premiership campaign ended in acrimony, anger and the possibility of legal action.

The Argentina forward scored the only goal in the defeat of Manchester United at Old Trafford, where the decision of Sir Alex Ferguson to leave out four first-choice players provoked ire at Bramall Lane.

Sheffield United were relegated at the end of their first season back in the top flight. They lost 2-1 to Wigan Athletic, who survived by virtue of a marginally better goal difference. Neil Warnock, the Sheffield United manager, questioned Ferguson’s decision and also criticised Liverpool for fielding an understrength team when they lost to Fulham last week.

“Sir Alex probably sold me a dummy in midweek and to see him celebrating on the pitch after being presented with the Premiership trophy leaves a bitter taste,” Warnock said. “You can blame everyone really, can’t you?

“What goes around comes around. Probably Chelsea will beat United in the Cup Final and AC Milan will do the same to Liverpool in the Champions League. I suppose when you’re a foreign manager like Rafa Benítez, he doesn’t give two hoots about what Sheffield United think, or anybody else.”

Warnock’s club will lose out on a minimum of £15 million in television revenue and more in gate receipts, sponsorship and commercial income. “It’s a gut-wrenching, horrible feeling,” Warnock, whose contract expires in the summer, said. He refused to discuss his own future.

The club are likely to pursue their threat of legal action against the FA Premier League for not deducting points from West Ham for breaches of the rules in the signing of Tévez and Javier Mascherano, the Argentina players. They have provisionally arranged a meeting this week with the other members of the “Gang of Four” – Charlton Athletic, Fulham and Wigan – angered by the League’s decision. They have asked for proof that Tévez has been eligible to play in the past three matches after the independent commission hearing into his transfer.

“West Ham staying up is not justice – for Sheffield to go down is not fair,” Dave Whelan, the Wigan chairman, said. “We are still solidly behind Sheffield and Charlton in this quest for justice. We set off down the road to justice and we will not come off the road until we get it.”

David Unsworth scored the winner for Wigan from the penalty spot six minutes into time added on in the first half. “It feels like I’ve just run the marathon,” Paul Jewell, the Wigan manager, said. “It’s a great achievement. The public’s perception of Wigan is probably the least attractive club.”

Needing to avoid defeat to stay up, West Ham ground out a 1-0 victory at Old Trafford. Tévez struck in time added on at the end of the first half, exchanging passes with Bobby Zamora, enjoying a lucky ricochet off Wes Brown and beating Edwin van der Sar.

Yossi Benayoun twice cleared off the line and a lacklustre United squandered other promising opportunities, but Ferguson defended his selection with the FA Cup Final against Chelsea next Saturday. “I don’t think I can be criticised, it was the strongest team at the end,” Ferguson said.

West Ham won seven of their last nine matches, including away victories over Arsenal and Blackburn Rovers, climbing from ten points adrift of safety to exit the relegation zone last week. Alan Curbishley’s side, remarkably, ended in fifteenth place.

“We have pulled off an amazing escape,” Curbishley said. “It was an unbelievable run when you consider the teams we had to play. I give great credit to the players. We had to get a result and we had the bonus of a win.”