Having played one game for Tigers in 2005, McDonnell was named as the probable replacement for winger Pat Richards, if he was unable to overcome an ankle injury, to take his place in the 2005 NRL Grand Final team.

[10] On 7 May 2009, McDonnell joined the Newcastle Knights mid-season for the remainder of the year, after being released from his Tigers contract.

[13] At the beginning of 2012, McDonnell joined the Hull Kingston Rovers in the Super League on a 1-year contract, following his former Knights assistant coach Craig Sandercock.

[16] In his first year at the club, he helped the team to the 2013 Challenge Cup Final against the Wigan Warriors where they were defeated 16–0.

[22] In 2016, he was called up to the Ireland squad for the 2017 Rugby League World Cup European Pool B qualifiers.