Hernandez has signed a new five-year contract at Manchester United worth in the region of £80,000 a week.
Eduardo Hernandez said: "We have renegotiated Javier’s contract and he is committed for five years to Manchester United. The initial contract was good for both Javier and the club because it enabled both to see if they could fit together and if he could achieve what was expected of him.
"Both sides have met their expectations and United were happy to reward Javier after his very good performances last season.
"United came up with a very good offer and I have nothing but praise for the way they have recognised Javier’s performances.
"I will not talk about numbers (wages), but it is a five-year contract."
His agent added: "This is a fixed salary with incentives based on the team’s success in each of the tournaments. We are very happy to reach an agreement with United.
"Javier was not badly paid with his initial contract, but it was his first one and, with respect, not comparable with the likes of Wayne Rooney and Nani. But today I can say that the contract was just signed and everyone is satisfied. It was never likely that Javier would leave."