(CNN) -- Manchester United are waiting on the fitness of England international Rio Ferdinand ahead of their vital trip to Wigan Athletic on Wednesday night.
Ferdinand is struggling to be fit to face Wigan as he battles a calf injury.
Ferdinand missed Sunday's 2-0 Manchester derby victory which left United needing just four points from their remaining three games to wrap up a third Premier League title in a row.
He is battling a calf strain with his replacement against City, Jonny Evans, also carrying a hamstring problem.
The versatile John O'Shea will partner Nemanja Vidic in central defense if neither Ferdinand nor Evans is fit to play.
Fellow defender Patrice Evra says United are not going to ease up with the championship in their grasp.
"The job is not finished yet," the French international full-back told Press Association.
"But if we win against Wigan maybe we can smile a bit more where the title is concerned."
United play fourth-placed Arsenal at Old Trafford on Saturday and finish with a match against relegation battlers Hull City and Evra is warning against complacency.
"In March we lost to Liverpool and Fulham, the first time since I arrived that we'd lost two league games in a row.
"I've never felt pain like that in my life before and I don't want to feel like that again," he added.
United clinched the title on the final day of last season with a 2-0 win over Wigan and the home side have been weakened by the absence of Egypt striker Amr Zaki, who has a knee injury while goalkeeper Chris Kirkland is doubtful.
Alex Ferguson may decide to rest Cristiano Ronaldo, who showed his displeasure after being substituted against City on Sunday.
Wayne Rooney, who came on for Ronaldo, is set to start after being rested while Carlos Tevez could also make way as question marks remain over his Old Trafford future.
The Argentine made a pointed gesture after scoring United's second against City, but Evra is full of praise for his teammate.
"Carlos is a world class player but he is also a very good professional," said Evra.
"He may have had problems but in all the time he has played he respected the shirt of Manchester United."
United are on course for a quadruple, having won the Club World Championship, the English League Cup and reached the final of the Champions League against Barcelona in Rome on May 27.