After joining from Rennes in 2004, Cech became a mainstay in the Chelsea side, helping the club to three Premier League titles as well as the UEFA Champions League and Europa League.
However, Thibaut Courtois' return from a three-year loan spell at Atletico Madrid has seen the Czech Republic international reduced to second choice.
Cech has made just two Premier League appearances so far this campaign, sparking speculation that he could look for a move away from Stamford Bridge.
Premier League rivals Liverpool and Arsenal have been touted as possible destinations for the 32-year-old and although the player's representative, Viktor Kolar, says a switch in January is unlikely, a transfer could be on the cards in the close-season.
"It's unlikely Petr will leave Chelsea in the January transfer window," he said.
"The club and coach want to keep him to help win the title. I think Arsenal should have made an offer to him. I think Petr would be considering it.
"Liverpool need to strengthen their position in goal and they know Petr will be available in the summer.
"We've been in contact with Real Madrid, but they don't need a keeper just now."
