The striker has been unable to match his England heroics with Saints so far this season.
A penalty on the opening day is all the normally free-scoring striker has managed in six Premier League starts, but manager Pochettino is not concerned.
"We are very happy and pleased with how he's playing, very happy with his contributions to the team and I have no doubts the goals will start coming from him as well," the Argentinian said.
"In addition to that, there is a new situation Rickie Lambert is going through - he's 31 years old and only now in the international side and there is a lot of expectation placed on him.
"It's something he has to adapt to that new situation he is going through, but we are very relaxed about his contribution and performances.
"I think he needs time to adapt to his new situation especially being 31 years old.
"I think it places a lot of physical and mental stress on him to be all of a sudden this big name in the international side.
"He needs to be able to withstand and adapt to that mental pressure and that physical pressure that he is facing at the moment.
"And also considering the fact he is a new dad and moved house as well - many things."