The forward has not been at his best for the Hammers this season, after an impressive last term.
He has one goal since mid-October, but Lopetegui is most focused on getting Kudus to work off the ball.
“I think any attacking player is much better if his focus is on his defensive work,” Lopetegui said.
“It always happens, when you are focused on your defensive work, normally your attacking performance is going to be better because football is about being focused always and a collective game.
“I think he was doing that but it was a pity he was out for five matches and it’s not easy to recover the rhythm in the Premier League.
“We are happy with him but we are happy because I think this is the only way and he has to understand football is a collective game despite each player having his strengths and his way to understand football.
"He is doing well and he is helping the team. When you do that, all of the other players are going to show that they are better. This is the only way I understand football, it is a collective game and on each one of them they have to put their best for the team.”