Hernandez, 23, has scored four goals in 13 appearance for the Old Trafford side this season after a stunning debut campaign in the north-west saw him net 20 goals in 45 matches.
The Mexican is challenging for a place alongside Wayne Rooney with Dimitar Berbatov, Danny Welbeck and Michael Owen, and insists the competition is healthy.
“It's not a problem," Hernandez told United's official website.
"I've come to learn that there will always be competition, at any club. You look around on the training pitch and there are almost 30 players, but only 11 can start a game. So it's tough.
"You'll always have disappointments. It helps you improve, though. On the training ground everybody wants to do their best, they want to prove what they can do and earn a spot in the team."
Welbeck, 20, who spent last season on loan at Sunderland, has come in for special praise from the Mexico international after his own fine start to the season.
The Mancunian has notched five goals in 12 games for Sir Alex Ferguson’s side and won his first competitive England cap against Montenegro last month.
"I remember when I was in Mexico and I was watching Manchester United on television - Danny was just starting to come into the team and be given a few chances," he said.
"You could see he had a lot of potential then, and was improving all the time. He was a good prospect then and now he's even better. He's had a great start to the season."
By Ian Woodcock
