Gary Cahill retired from international football in August after 61 England caps in a bid to prolong his club career. He is yet to play a minute following six competitive matches of Chelsea's 2018-19 season.
The veteran defender has admitted he will likely leave the Blues in January after being left out in the cold by new manager Maurizio Sarri. Thursday's 1-0 win at PAOK Thessaloniki was the first time Cahill was called into a matchday squad this campaign, but he failed to emerge from the bench as Antonio Rudiger and Andreas Christensen were preferred in the center of defense.
"I don't want to jump the gun, but as things stand at this time, probably, yes," the 32-year-old replied when asked if he could leave in the new year, as reported by The Telegraph's John Percy.
"I'm not a guy who is willing to accept not playing. It's all about playing. Your career's short enough as it is. I've got maximum respect for everybody here at the football club, for the fans and all the players. But sometimes you have to make tough decisions to keep your career going forward."
Cahill joined Chelsea from Bolton Wanderers for £7 million in January 2012, and has since collected two Premier League titles, two domestic cups, and honors in the Champions League and Europa League. He inherited the captaincy from John Terry when he left at the end of his contract in 2017.
Cahill's own deal expires at the end of the current season, so he should be available for a reasonable fee if Chelsea entertains selling him in the January transfer window.
The Blues have a perfect record to begin the campaign and seek a sixth consecutive Premier League win when they make the short trip to West Ham United on Sunday.