Collymore wrote in the People: "When it comes to United players not stepping on to the next level, I would point to Michael Carrick as someone who has more to prove than Rooney.
"Some have been raving about him and I get a lot of abuse for getting on his back, but I believe that Carrick does not offer United enough on big occasions.
"In the Premier League he is fine. A very good, reliable player who can dictate matches and help you win the title.
"But in the Champions League you have to have more about you and too often I see him sat deep, just in front of the back four, simply shutting down players and space. Any decent midfielder could fill that role.
"For me, that is not the sign of a top-quality midfielder. He struggles to dominate these big matches."