Ole Gunnar Solskjaer's men have been in prolific form since the Premier League returned to action, although Rashford, who has notched up 15 goals in the league so far, has only managed to bag once in United's last five matches.
Fernandes, Anthony Martial and Mason Greenwood have all made headlines for their attacking returns as of late, but Fernandes is confident that Rashford will rediscover his goalscoring touch in the near future.
Speaking to the official Manchester United website, Fernandes said: "Like you saw [Thursday], Mason [Greenwood] scored a beautiful goal again and Anthony [Martial] and Marcus did very well.
"I think everyone is talking about Marcus not scoring a lot of goals but he is doing an amazing job. The game he is playing now, maybe he is not achieving his goals and everything but, with everything we are doing now, he will achieve more goals and more assists.
"In the games, in the complete football, because football is not just about goals and assists, it is about the team and Marcus is playing very well for the team.
"Anthony is playing very well and scoring goals, which is what you want as a striker, and Mason is a young kid who is scoring every time in different ways, so you always need to expect something new from him.
"I hope Marcus can find more goals because he deserves it for the work he is doing for the team, and nobody sees it because everyone sees the goals and who scores and assists. The work he is doing for the team is amazing.
"Marcus was injured for a long time so it's difficult to find that confidence again, to do things like shoot from far out. But he is doing an amazing job for the group and I think he deserves credit for this."
United continue their charge for a top-four finish when they welcome Southampton to Old Trafford on Monday, and the Red Devils can leapfrog Chelsea and Leicester City into third should they pick up all three points against the Saints.