Serbian defender Nemanja Vidic is expected to start the Champions League semi-final first leg against Barcelona in the Nou Camp next week, despite sitting out training last night.
Vidic only returned to the side from a knee injury in the 1-1 draw against Blackburn at the weekend, but said after the match the knee felt sore but that he was "ready for the next game".
The prospect of losing Vidic ahead of such a high profile encounter with such an attacking side would be an unwelcome one and centre-back will therefore be given every opportunity to prove his fitness.
He will undergo medical tests today, as will England full-back Wes Brown, who picked up a knock at Ewood Park.
He trained away from the main group in Barcelona last night. If one or both of the defenders fit-again Mikael Silvestre is available, while Ferguson could also call on 21-year-old Spaniard Gerard Pique.
Brown and Vidic have formed on half of the meanest defence in the Premier League this season.
Along with Rio Ferdinand and Patric Evra they have conceded just 29 goals in 51 games and have kept 28 clean sheets.
