The influential Scotland captain took an enforced break last season after being diagnosed with ulcerative colitis and there is no suggestion yet that he will be able to take part in any of the pre-season campaign.
When asked by MUTV about any comeback for the 28-year-old, Sir Alex replied: "We’ll wait and see about that. Obviously the boy is trying very hard to get back to his level.
"It’s not going to be easy but we’ll give him every possible chance and we’ll see how he does. He kept himself active towards the end of the season when he replaced Paul Scholes as a reserves coach when Scholes decided to come back to the fold as a player. Darren's a terrific lad and we all hope he can come back."