The Red Devils travel to Bramall Lane on the back of five wins in their last six games.
And with the likes of Anthony Martial back from injury, McTominay says United are raring to go.
He told reporters: "With the injuries we've had, I do think we've coped relatively well with a small squad and a lot of boys playing a lot of minutes in a short space of time.
"I think people forget that we have had a lot of injuries as well, and you can see with Anthony (Martial) coming back, what a difference he makes.
"There are very positive signs and things are changing. Everybody is looking forward to the next game and wanting that next game to come as soon as possible.
"Everybody wants to play and that's the sign of a healthy dressing room."