Chelsea meet Real Sociedad at Stamford Bridge and plan to parade their full senior squad on the pitch before the sold-out match.
"Lampard is our history, but Fabregas is our future, Mourinho told the club website (www.chelseafc.com), adding that both he and his players believe the Spaniard is the right man to play in central midfield.
"Frank is the history of the club, history nobody can forget," said Mourinho. "Fabregas is the future. History is history, but the future is more important at the moment.
"My opinion, and the opinion of my players, is that Fabregas is the right player to occupy that central position in midfield."
Chelsea beat Ferencvaros 2-1 in Budapest in a friendly on Sunday courtesy of goals from Ramires and Fabregas, who impressed after his introduction at the interval.
"They (Ferencvaros) fought for a result until the last minute and that was good for us," said Mourinho. "They competed and that was important."
Fabregas' solo goal capped a fine display that convinced many observers that he will be a more than adequate successor to all-time Chelsea top scorer Lampard.
Lampard, 36, left Chelsea in June to join MLS outfit New York City. He is currently on loan with English champions Manchester City.
In another website message, the club said Mourinho requested that supporters going to the sold-out match at Stamford Bridge arrive in time to herald a parade of the entire first team squad.
"It is the first time we have hosted a friendly at our home since 2006 - and it promises to be a memorable evening, with the sold-out crowd given the opportunity to welcome each of the players," said the club.
After signing midfielder Fabregas, striker Diego Costa, left-back Filipe Luis and returning club legend, striker Didier Drogba, along with recalled loanees defender Kurt Zouma and goalkeeper Thibaut Courtois, Chelsea are tipped as favourites to depose Manchester City as Premier League champions.
The league starts on Saturday, but Chelsea are not in action until they visit promoted Burnley on Monday -- a fixture for which Mourinho is confident his team will be perfectly prepared.
"It's been a difficult pre-season because we started with seven players," said Mourinho. "After that, step by step, players were arriving after the World Cup and holidays.
"Finally, in this last week, we've had everybody together, but obviously not everyone is prepared. For example, (Branislav)Ivanovic has been training for one month, (Andre) Schurrle has trained for five days.
"So there is a big difference between players. We have to play the first league match next weekend and we will be ready for that."