Wayne Rooney is "desperate" to play against Liverpool on Sunday, but Sir Alex Ferguson still has doubts over the fitness of United's no.10 and team-mate Darren Fletcher ahead of the visit to Anfield.
Rooney has been struggling with a calf injury and missed the games against Bolton Wanderers and CSKA Moscow in the last week, while Fletcher was also absent for both matches with a foot injury.
"On the injury front I can't give a clear picture, there are still some doubts about Rooney and Fletcher," Sir Alex said on Friday.
Getting the influential pair ready for the game is now the major aim for United's medical and coaching staff, though Sir Alex doesn't doubt their keenness to return, particularly Rooney's.
"He is always desperate to play, that's the nature of the boy," said the boss. "Of course, you can't let that cloud the realistic side of things. It's going to be important how he does in training on Saturday. We'll see if Wayne does train on Saturday and then we'll have a better idea."
The good news for United is that Patrice Evra and Ryan Giggs, who both picked up knocks against Bolton and didn't travel to Moscow, have both been passed fit, while Ji-sung Park has definitely been ruled out.
"Patrice is fit, and Ryan is also fine, but Ji-sung is out unfortunately," the boss added. "Everyone is fit from after Wednesday's game in Moscow."