The Manchester United striker's future is currently uncertain following reports that he wants to leave the Premier League champions.
"I could see him in a Chelsea shirt," Cech told Sky Sports News. "Players can change shirts and obviously he had a fantastic career with Manchester United and sometimes players need new challenges.
"Sometimes the consequences are the way that you are looking for the new challenge and change of the shirt.
"So if that happened, obviously he is a fantastic player and he will be welcome to our squad but now we are only in the moment of speculations about it so we will see what this week will bring."
Rooney is expected to hold talks with new United boss David Moyes on Wednesday to decide if he will stay at Old Trafford.