LONDON (REUTERS) - Manchester United midfielder Phil Jones is a doubt for the first leg of the Champions League last 16 tie against Real Madrid on Wednesday after injuring his calf against Everton.

Jones, who was superb in shackling Everton dangerman Marouane Fellaini during Sunday's 2-0 victory, will be central to manager Alex Ferguson's plans for the Bernabeu clash.

However, he limped off early in the second half and Ferguson said they did not yet know the full extent of the problem.

"He got a kick in the calf and we'll have to monitor it," Ferguson said.

Central defender Jonny Evans also had to come off suffering with cramp but should be available for the Madrid match.

"I think he's just lacked a couple of games," Ferguson said.