Fonte suffered a frustrating start to his Hammers career on Wednesday night as his side failed to produce the same level of performance they have shown in recent games.
The Portuguese defender is refusing to dwell on the defeat and is already looking to put things right as he prepares to make a quick return to St Mary's Stadium this weekend.
Fonte played over 250 games for the Saints, but is now focused on helping his side get straight back on the winning trail.
Fonte said: “We are prepared to work and get it right. It was not a good day against Manchester City and we started the game badly.
“When you give a team like City a head start normally there is no way back. It is not what I want but I am prepared to put the work in and and improve.
“We worked on a game plan during the week and when the game started we did not apply it. We tried to over play in areas that the manager said not to.
“We should have gone with a game plan that would be to explore the play behind and in the flanks and we need to improve.
“I am experienced enough that when the team has a bad day it is difficult for everyone not only me, but it is not a problem for me as I am still breathing and I am prepared to put the work in. I am looking forward to the next one as I want to win.”
When you give a team like City a head start normally there is no way back. It is not what I want but I am prepared to put the work in and and improve.
Fonte also wants to put things right for the fans who stayed behind the team despite a disappointing evening at London Stadium.
Fonte added: “What can we can say? We lost when we are at home. No one likes it. The fans are disappointed and we apologise and we want to put it right for them.
“They deserve everything and all our sacrifices. That is what we are going to do.”