Goalkeeper Petr Cech has endorsed Chelsea's pursuit of "great player" Wayne Rooney and knows nothing can be discounted in football transfer business.
Chelsea have offered Rooney a route out of Manchester United, but a bid was rejected by the Barclays Premier League champions despite the apparent desire of the striker to leave and there is some way to run in the bid for his services.
"Wayne Rooney is a great player but at the moment he's a Man United player," Cech said. "We'll see what's going to happen. He's a great player. Let's see.
"You always want to have the biggest and strongest squad so you can challenge for titles. That's why you have a manager and sporting director to take care of that and you have to do the most important part and that's the work on the pitch.
"We already have a few more players and a great squad. If the manager doesn't think we have enough he will try to get players in. It is only his decision.
"For players, we concentrate on getting fit and doing our best, to play as much as we can. That's all we can do. In football things are changing every day with every squad. As time goes on, every team can make some changes. Anything can happen."
Mourinho, whose second spell as Blues boss began with a 1-0 win over Singha All-Stars in Bangkok on Wednesday, has already signed Andre Schurrle, Marco van Ginkel and Mark Schwarzer, the latter providing back-up to Cech.
Cech is one of the survivors from the Special One's first spell at Stamford Bridge, when Chelsea won a first Premier League title in 50 years in 2005 before retaining the trophy as the Portuguese established himself as the most successful manager in the club's history.
Cech sees little alteration in Mourinho after nearly six years away. "He is as hungry as ever, he wants to be successful," Cech said. "When you have someone who works at such a high standard every day it never changes. It's the same."