Red Devils manager has confirmed that the midfielder has a chance of playing in the European final at Wembley, and has revealed that his training will be stepped up
The 27-year-old midfielder was suffering from a stomach virus and had not featured for the club for two months before facing Schalke in the second leg of their Champions League semi-final.
But with the Scotland international still struggling for full fitness, Sir Alex told reporters: "Darren has put the weight back on and is back in training, but he has a bit to do yet. But, as far as the final is concerned, there is almost three weeks to achieve that.
"If he does reach the target, it will be a big boost to us as we all know he is big-game player.
"The 20 minutes he got against Schalke last week was certainly a step forward. His training, in terms of sharpness for such an important game, will be stepped up now."