Wayne Rooney will miss Manchester United's Premier League game away to Blackburn Rovers on Sunday after re-injuring his ankle in the Champions League quarter-final exit against Bayern Munich on Wednesday.
The striker, whose 34 goals have underpinned United's title challenge, lasted 55 minutes against Bayern after making a surprisingly fast return to action, just a week after damaging ankle ligaments in the first leg.
"I don't think it's as serious as we said the first time, but I think he'll be ready for the (Manchester) City game," manager Sir Alex Ferguson told the club website on Friday.
"We've got more time to work on it, anyway. Other than that everyone else is fit."
Arsenal's injury-hit squad could soon be boosted by the return of Dutch forward Robin van Persie, who is set to return from ankle ligament damage sustained in November.
"Robin will be joining the squad for full training imminently," physio Colin Lewin told.
City, who are favourites to finish fourth, are also likely to be without Micah Richards for Sunday's clash with Birmingham City because of a knee injury.
Struggling West Ham United will be without suspended influential midfielder Scott Parker for Saturday's match at home to Sunderland.
Young striker Louis Moult could be selected for 10th-placed Stoke City's match at Wolverhampton Wanderers on Sunday if club top scorer Ricardo Fuller does not feature.
"If he doesn't play, then Louis will come in for him. The lad has done very well in the reserves this season," Stoke manager Tony Pulis told the club website.
