Lampard is entering the final year of his contract and revealed this week the club had yet to follow up last term's initial talks about a new deal.
The 34-year-old insisted he would "love" to stay on but there now appears to be a real prospect he could leave next summer.
Blues boss Di Matteo was coy about revealing whether he had recommended to the Chelsea board that Lampard was offered an extension but asked whether he was hopeful there would be a successful conclusion to any talks, he said: "I am, yes."
He added: "These are talks between the club and the player.
"I've been very happy with Frank and he shows his qualities that he has in every game that he plays, so a very influential player within the group as well."
The same could be said for Didier Drogba but Chelsea decided to allow him to walk away this summer rather than cave into the striker's contract demands.
Speculation over Drogba's future was rife during the whole of last season and the same will happen with Lampard until his own situation is resolved.
But Di Matteo said: "I don't think I'll be answering this question all the time.
"I think that's between the player and the club to sort out and when that's going to be, when the time is going to be."
Chelsea have shown a reluctance to offer players in their 30s anything longer than a one-year contract but Di Matteo had no fears about Lampard's ability to star at the highest level for some time to come.
"He's in good shape, he's not suffered any major injuries and he looks after himself," he said.
"We've seen that many players who live a professional life can go on and play up to their late 30s."
However, that will almost certainly involve the man who is closing in on becoming Chelsea's record goalscorer being used in a more withdrawn midfield role.
The Blues have an embarrassment of young, attacking talent in advanced areas but Di Matteo said: "I don't think we're going to change exactly everything there is about Frank and take his qualities away. We want to enhance his qualities within the team.
"He certainly has a little bit of a different role but we're still wanting to do what is best for him, trying to go forward and he's got good timing or arrival in the box and scores goals for us as well."
Lampard may also need to get used to having his game time rationed, something the midfielder took issue with last season and played a part in Andre Villas-Boas' demise as manager.
Di Matteo said: "We have a lot of competition in midfield - that is very good - but we have a lot of games as well and competitions that we're going to be playing in.
"So, there will be time for everybody and that's the situation for all the players."
He added: "He's an important player, Ramires is an important player, [Juan] Mata's an important, [John Obi] Mikel's an important player, [Michael] Essien.
"We can't think that we can only count on 11 players or 10 players."