According to the British media "The Guardian", Crystal Palace may face five games in 11 days in December, with opponents including Manchester City and Arsenal.
After defeating Liverpool in midweek, Crystal Palace advanced to the top 8 of the League Cup. They will face Arsenal on Tuesday, December 16th or Wednesday, December 17th for a quarter-final contest. The Guardian stated that since Crystal Palace will face Finnish team Kups in the UEFA Europa League on December 18, the game against Arsenal may be scheduled for December 16.
On Sunday, December 14, Crystal Palace will play against Manchester City in the Premier League. This game was originally scheduled to be played on Saturday, but Crystal Palace will play against the Irish team Shelbourne in the UEFA Europa League on December 11, so the game with Manchester City has been adjusted to Sunday. On December 21st, Crystal Palace will face Leeds United in the Premier League.
To make things more complicated, Arsenal still has two Champions League games in January, and the first leg of the League Cup semi-finals will start on January 13. Crystal Palace and Arsenal are understood to be in discussions with the English Football League but there appears to be little wiggle room amid a packed schedule.