Thiago Motta may be out until 2018 after Paris Saint-Germain announced the veteran requires minor knee surgery.
The Brazilian-born Italy international has started 12 matches for Unai Emery's team in all competitions this term.
But, should he go under the knife imminently to address the issue, Motta may not return until after the mid-season break.
Leading Group B in the Champions League by three points, PSG host Celtic in Europe next week, followed by a trip to take on title-holders Monaco, who are four points behind them in second place in the league, four days later.
PSG do not then play again until the Coupe de France the weekend of January 6/7.