The Red Devils are currently in seventh place in the Premier League table, 14 points adrift of leaders Arsenal.
"You have to feel for the new manager," he told Sky Sports News. "He has had no luck at all, but we are not going to feel sorry for ourselves.
"It is going to be very tough. I would say we will need to win every game from now until the end of the season to [win the league] but you should never rule us out."
United return to action on Wednesday night when they will look to overturn a 2-1 first-leg deficit at home to Sunderland in the League Cup semi-finals.