Wood helped bring through Garnacho as academy coach.
"I'm a little bit surprised [at this season], he always had the potential, you watch him in youth games, even the year before the Youth Cup when he was playing for Neil Ryan's under-18s, he was showing some glimpses of some real high-level stuff. You knew there was a player there but it would take some time with his physicality and mentality," he told the Manchester Evening News.
"He finished last season really well and I thought his next challenge would be to really stand out in 21s games, but he seems to have bypassed that. The main thing for him is he's taken his chance, that's the main thing for any player coming through there, you look back at Marcus [Rashford], he took his chance when it came. It's the type of club where they will always get an opportunity and if you can do what he's done and take your chance you will get more chances. It's been good to see him do that."
Garnacho has been on the end of some tough love at United as well, with Erik ten Hag and Bruno Fernandes critical of his attitude in pre-season. Those public comments were a sign of how highly rated he is as well, and Wood is hoping the teenage winger takes the advice on board.
"I know there's been a lot of messages from Bruno and the manager, I just really hope he takes that on," he said.
"He's a good kid, I do think he wants to improve, he loves his football, when those guys are saying that you've got to be wise and take that on the chin and digest that and make sure it doesn't get thrown at you again. I really hope he does that."