The England striker was addressing claims that he handed in a transfer request at the end of last season, something he feels that the Scot has clarified in his new autobiography.
"He's come back and corrected the story that I put a transfer request in," he told Sky Sports News. "He's gone back and proven that I didn't.
"He's obviously got his own opinion. I've not seen him since he retired and I'm happy under the new management. The other stuff doesn't concern me.
"That's the past, I'm looking to the future now."
United are now one point clear of Bayer Leverkusen at the top of Gruop A in the Champions League.