United are preparing for the English showpiece final on Saturday afternoon. Lukaku is the club's only major injury doubt for the game.
He is recovering from an ankle injury he sustained against Arsenal last month.
"I've watched him all season, like everybody else," Cole told ManUtd.com.
"I think he looks fantastic. To get the goals he's got this season, in a team that doesn't create loads of chances for him, he's done brilliantly and really well considering it's his first season at Old Trafford.
"It's not nice when you've got that little bit of rhythm and pick up an injury. You know you've got a massive game coming up and are a bit touch and go or whatever. So it may be difficult for him but, hopefully, he'll be passed fit and do the best he can.
"It's not every year you're going to get to the FA Cup final. There are no doubts that, if he's even 90, 80 or 70 per cent fit, he'll give it a go."