The 35-year-old had been dubbed a 'box-to-box' midfielder in the peak years of his career, but his age, and competition for places at Stamford Bridge, has forced him to adjust to a new way of playing.
Lampard has largely been used in a holding-midfield role this season, and Mourinho admits that it is natural for players to have to adapt, which he thinks that the England international is doing to good effect.
He told reporters: "I don't think he or anybody can play the same football, the same characteristics of his football, when you are 20 to when you are 35. You have to play differently, adapt to a new situation, which he is doing very well.
"We are playing with two midfielders and a number 10. The two midfielders are more positional. They don't need to go forward as much because we have four attacking players permanently. This is good for Frank in his new life as a more mature player.
"He is in a stable moment in his career and can keep this stability for quite a time. His game and qualities are very adapted to Chelsea and the national team. They also play with two midfielders and one behind a striker, so he's more of a positional player. It's easy for him."
Lampard has started five of Chelsea's seven Premier League games this season and all three of their European matches, contributing two goals.