In the following season, Muldoon continued to play for Ireland A. He started against Argentina A in an end-of-year game on 27 November 2009, which ended in a 31–0 victory for the Irish. On 31 January 2010, he started for the A side, now renamed the Ireland Wolfhounds, against England Saxons in a warm-up game for the 2010 Six Nations, which ended in a 17–13 defeat. At the end of the season, Muldoon was included in the senior squad for the 2010 summer internationals. He started for Ireland in an uncapped match against the Barbarians in Thomond Park on 4 June 2010, which Ireland lost 23–29. On 12 June 2010, Muldoon started for Ireland against but was forced from the field with a broken arm 36 minutes into a 66–28 defeat. The injury meant he missed the remainder of the tour. Muldoon didn't play for the Ireland Wolfhounds again until 28 January 2012. He started at blindside flanker against the England Saxons in a 2012 Six Nations warm up game, which the Wolfhounds lost 23–17.