The Reds' boss revealed on MUTV's Countdown to Kick-Off on Friday that United had reached agreement about a new contract for the midfielder, but said the player himself has still to decide whether or not to sign it.
"We've agreed a deal with his agent. It's now down to the boy," Sir Alex told MUTV.
"I must stress, he's going to be a first-team player. There's no doubt about that.
"The boy has great potential and I think he's at the right club. But he has to make that decision."
The 19-year-old, who helped the Reserves clinch the Barclays Premier Reserve League North title on Monday night, has certainly impressed in his seven senior appearances this season - all as a substitute.
Unfortunately though, we're unlikely to see him in action again this season after he suffered ankle ligament damage in United's stunning 6-3 comeback at Newcastle that sealed the title crown.