Chelsea won the Premier League title by eight points last season but Mourinho is determined to ensure they remain ahead of their main rivals.
The Portuguese manager confirmed yesterday that Filipe Luis and Mohamed Salah would be allowed to leave the club this summer.
Luis only arrived at Stamford Bridge last summer for £16m from Atletico Madrid but struggled to make an impact, starting only nine games.
And the Blues are in talks with the La Liga club about the Brazilian left-back returning to the Vicente Calderon.
Salah meanwhile spent the second half of last season on loan at Fiorentina and will not be with Chelsea this season as there is not enough room in Mourinho's squad.
"If they want [Luis] back then they have to pay and we have to discuss the offer," Mourinho said.
"Then we have to react and we have to go in the market.
"I see Salah's future elsewhere, either as a loan or an offer that we are happy to accept.
"At the moment, with Hazard and Willian, Traore, Moses and Cuadrado, we have five players for these positions. It is better not to have so many."
Juan Cuadrado could also depart Stamford Bridge with the Daily Mirror claiming Chelsea are ready to listen to offers for the Colombian.
The 27-year-old arrived on transfer deadline day in the winter window but struggled to make an impact and he will be allowed to leave just seven months later if Chelsea can recoup his £23.3m fee.
Two players could head to Leicester on loan with former Chelsea boss Claudio Ranieri interested in Oriol Romeu and Nathan Ake, according to the Daily Mail.
Ake is also interesting Newcastle and Watford.
And a host of clubs are interested in signing striker Patrick Bamford, who starred on loan at Middlesbrough last season, after he was omitted from the club's preseason tour.
