"I think it's the way his mentality works," Rashford told the club's official website.
"That is probably the biggest thing, not only for the young players but other players can take that from him as well.
"In fact, that is definitely the main thing. It's good for the dressing room. Sometimes, if we're down, he can pick us back up and, when we're up, he keeps us up. Bringing in that type of player, it has been key."