Owen is expected to complete a surprise switch to Old Trafford, just two days after he became a free agent when his contract at Newcastle expired.

There are concerns about Owen's fitness, with the outcome of a medical seemingly the only thing blocking the deal.

However, Rush has no doubts Owen can prove his class with the Premier League champions.

He told Sky Sports News: "People have knocked Michael Owen all his career but he comes back bigger and better. People said he was finished years ago but he's a fantastic player who comes back stronger and better.

"It (the talk) won't worry him, I know the way he is and he doesn't have to prove anything anyway. It's a chance for Michael to get back and score some goals. He'll get chances for Manchester United and will score goals."