Paris Saint-Germain are considering an £8million bid for Terry, while 34-year-old Lampard is the subject of long-standing interest from MLS side Galaxy.
But Di Matteo said: “They will be here next season for sure.
“It is not a question of overhauling the squad, it is a question of finding the right players to integrate into the team. The team will change face over time as the players move on or retire.
“Frank’s contract is a matter between the club and the player.
“He has been a fantastic servant to the club and the club will make the decision with him and see if they are happy to go on. But he will be here next season.”