The ex-West Brom boss, who has returned to his former club as Andre Villas-Boas' No.2, believes the midfielder will stay at Stamford Bridge despite recent speculation
The midfielder, who turns 34 this summer, has been continually linked with a move away from Stamford Bridge recently, as his first-team opportunities become increasingly limited under Andre Villas-Boas.
However Matteo, who joined the club at the start of the season to work under the Portuguese boss, rubbished the possibility of the England international departing the Blues in the near future.
“I can't see him leaving this club," said Di Matteo.
“He has been here for 10 years and he's part of the successful history of this club.
“I don't know what the future will hold but I can't see him going anywhere, he is part of our plans and important for us.
“We are very happy Frank is in our team. He's a fantastic player and has been a fantastic player season after season for this club and for his country.
“It is not a surprise other managers like him. It is not [unsettling] for us. He's old enough to deal with these kind of stories and so are we.”
The former West Brom boss also revealed the west London side are gradually getting closer to completing a deal for Bolton centre-back Gary Cahill, as they look to agree personal terms with the 26-year-old.
“A fee has been agreed and there are ongoing negotiations for personal terms,” Di Matteo said.
“He has developed into a top central defender in the Premier League. He has made selection for the England team, he's a very good age.
“He would add very good qualities to our squad.
“I wouldn't expect too much to happen in this market. We are happy with the quality we have. We are very happy with the team, with the players we have.”
Didier Drogba and Salomon Kalou are notable absentees for Chelsea’s third-round FA Cup clash with Portsmouth on Sunday, with the Ivorian duo forced to report for African Nations Cup duty prior to the game.
Di Matteo revealed: “We tried to have them available for the FA Cup game but their coach was adamant everybody was going to be there on Saturday for the African Nations' Cup.”
Club captain John Terry is also a doubt for the tie, with Di Matteo insisting a decision will be made on Saturday as to whether the defender will feature.
He said: “He has been playing with a knock on the knee. We will have to see how he is. He has played with an injection. We will see how he feels.”