Everton defender Leighton Baines sustained a broken toe in Saturday's Merseyside derby and could be out for up to six weeks, potentially scuppering his chances of a January transfer to Manchester United.
The England left-back was forced off early in the second-half after Liverpool midfielder Jordan Henderson accidentally trod on his foot.
Baines left Goodison Park walking unaided - despite being given some crutches to use - but the Toffees' medical team cannot put a definitive timescale for the 29-year-old's recovery, with it estimated to be between 10 days and six weeks.
Although David Moyes said United's interest in Baines was "dead" back in September, it is understood the champions are preparing a January transfer window move for the Evertonian.
Baines' contract at Goodison expires in summer 2015, and the timing of a January raid gives Everton, who value him at £20 million, the upper hand in negotiations.
United had two summer bids rejected for Baines, and their dismal dealings in the summer transfer window have put pressure on Moyes to strengthen a flawed squad mid-season.
Marouane Fellaini was United's only major signing on deadline day - at £4 million more than he could have been bought for.
Supporters might argue that while United lack competition for Patrice Evra, their midfield is in greater need of reinforcements. Fellaini's disappointing start and Michael Carrick's injury have left Moyes with uninspiring alternatives Tom Cleverley and Anderson, with United still semi-reliant on Ryan Giggs, who turns 40 on Friday.