Gardner was then an important part of Crystal Palace's defence in 2011–12. He played all 120 minutes of Palace's "stunning extra-time victory at Old Trafford" on 30 November 2011, as they defeated Premier League champions Manchester United 2–1 to reach the semi-final of the League Cup. He scored with his head for the home team at both Selhurst Park and the Cardiff City Stadium in the semi-final, leaving the tie level at 1–1 after two legs; Cardiff City won the subsequent penalty shoot-out to deny Palace a place at the final. Gardner was short-listed for the club's Player of the Year award at the end of the season, though the award instead went to fellow defender Jonathan Parr. Palace offered him a new contract, but it quickly became apparent that Gardner would instead be moving to a new club.