The 24-year-old Mexican was left out of the United side that beat Liverpool 2-1 on Sunday, despite having scored three goals over the previous three games.
But Hernandez told the club's official website: "I still think there is work for me to do. But the reason I want to improve is so that I can help the team.
"It's not just that I want to score more goals. It's a group sport and so I want to do what I can to help the team get the right results every week.
"I'm not saying I'm the perfect player. I am always looking to improve my game, whether that's my play outside the box or also inside it."
Hernandez's current tally of 12 goals is bettered only by United's top-scorer Robin van Persie and the Mexico international feels the league leader's style of play is well-suited to his own.
"In the history of Manchester United, the team plays a very direct, attacking game," he added. "We want to get to the goal as quickly as we can. We want to play with speed.
"But the important thing at this club is that we can express ourselves. Every time we go out on the field the gaffer tells us, 'Go out, enjoy yourself and do your best' and that's been important to us doing well so far this season."