However, Jonny Evans is now set to return from an injured ankle which has kept him out of action since the end of last season, and is expected to partner Nemanja Vidic at the heart of the back-line when the Red Devils take on Southampton at St Mary's on Sunday.
Rio Ferdinand, Chris Smalling and Phil Jones have all been kept out of action too due to injury, but Evans insists that everyone is recovering well.
He told United's official website: "There is plenty of strength in depth in the squad. We’ve had injuries, but everyone is coming back slowly but surely.
"The squad is so strong; just looking at the numbers we have in training is unbelievable.
"It’s important to have that, though, because you get injuries through the season and we want to do well in every competition we play in, so we’re going to need everyone."
The defender played a full 90 minutes during the week, starring in United's under-21 team as they defeated Tottenham 2-1. However, Evans still believes he is behind his team-mates regarding his fitness.
"I had the operation and I was hoping to be back for some of the pre-season games but I had a couple of setbacks with it," he said. "I feel good now, but I know I need to work that bit harder because I’m a bit behind everyone else."
The 25-year-old also called on his team-mates to maintain their form away to newly-promoted Southampton on Sunday.
"We’ve played a couple of FA Cup games there in the last three years and managed to win both so hopefully we can continue our form there."