Alexis is currently on-loan at Inter Milan this season, but is expected to return to United for preseason.
"I wouldn't rule out Sanchez going back to United and being a key part of their team next season. Football is a funny old game," Ince told Paddy Power.
"I've been in the situation as a manager where I've thought, 'right, I'm going to get rid of him and him', but when it comes to it you can't get the deal done, so they stay at the club.
"Then pre-season comes around and they're a totally different player to the season before, and they're your key man the next season.
"So Sanchez could definitely go back to United, look fantastic in training, and bang suddenly he's important to their plans after all."