 Due to his poor performances in his first season and the arrival of German international Per Mertesacker in the summer of 2011, Squillaci fell down the pecking order at the club ahead of the 2011–12 season.He made his first appearance of the season in the League Cup round win against Bolton Wanderers and continued to be a part of the League Cup squad, playing in the quarter-final defeat to Manchester City.He made his first Champions League appearance of the season on 6 December 2011, where he played the full 90 minutes in Arsenal's 3–1 away defeat to Olympiacos, Arsenal's final group stage match.