Manchester United's Rio Ferdinand has an outside chance of playing in Wednesday's Champions League quarter-final first leg against Chelsea.
Boss Sir Alex Ferguson had raised doubts over his ability to get back on the pitch before the end of the season.
But, on Friday, he confirmed that the deposed England captain has returned to training, though he is more likely to return from injury next weekend.
"I have to decide," said Ferguson, who is missing some key defenders.
Ferdinand, 32, has not made an appearance since suffering a calf problem in the warm-up prior to United's Premier League defeat at Wolves at the beginning of February.
Yet the former West Ham and Leeds defender resumed training this week and, so far, come through without a reaction.
That means Ferguson must decide whether to put Ferdinand through another training session on Saturday - when his team-mates take on West Ham - in the hope that he could be rushed back to face Chelsea, or hold him back until next week's match against Fulham on Saturday, 9 April.
"He has only been training two days and then just a light session today [Friday]," Ferguson said.
"I have to decide whether we bring in him tomorrow, or give him a day off and start him on Wednesday again. He is more likely to be fit for Fulham."
Rafael, John O'Shea and Wes Brown will all be unavailable for the trip to Stamford Bridge, though Jonny Evans can play in Europe while he serves a three-match domestic ban.
Brazilian midfielder Anderson is likely to be on the bench at Upton Park after recovering from a knee injury, although it had been initially suggested that the problem would rule him out for the season.
But fellow midfielder Darren Fletcher is still troubled by a virus, whilst Owen Hargreaves' United future now looks to be in serious doubt after he picked up a shoulder problem in training.
"It is another huge setback for the lad," said Ferguson.
Hargreaves has not featured for United since he was forced off with injury after 10 minutes of their 2-1 win against Wolves in November - which was his first start since September 2008 - and his current contract expires this summer.