The 31-year-old called time on his England career after the FA charged him with using racist language towards Queens Park Rangers defender Anton Ferdinand.
Terry is expected to return to Di Matteo’s starting line-up for the clash against Liverpool on Sunday after serving a four-game ban for abusing the Hoops centre-half.
The Chelsea captain has been linked with a move away from Stamford Bridge in recent weeks, but Di Matto backed Terry to remain at the club for many more seasons, aided by his decision to quit representing the Three Lions.
“During the international break we will train,” said Di Matteo.
“The small group that remains here joins up with the youth team, so we get a good look at all our players.
“Normally, it’s more youth team players than our senior players – it’s normally only three senior players.
“For the youth players, it will be great to have John Terry around and to play with him in training.
“It also probably gives John a good chance to prolong his club career by another year or two if he is not involved internationally.
“It certainly helps when you can have a little break in a normal week, especially with the schedule we have.”
He added: “Absolutely, John Terry is still our captain and leader, and I think he will be playing for many, many more years.
“He remains a fantastic defender and leader.”