Career
The defensive midfield player has played for Bohemians, Carlisle United, Shamrock Rovers, Glentoran and Monaghan United. He made his Rovers debut on the 18th of March 2005 and went on to make a total of 31 appearances in all competitions scoring 6 goals. McDonagh arrived at The Oval in January 2006 from Shamrock Rovers, and was one of former manager Roy Coyle"s final signings before resigning.
McDonagh scored his first goal for the club in a 3-2 success against Newry City at the Oval in March, this would be his only for the season.
2006/2007 was a mixed year for McDonagh, with consistency being the main hindrance to him becoming a favourite with the Glentoran crowd. This is McDonagh"s only winners medal to date.
In 2007 McDonagh was placed on the transfer list. In February 2008 he was loaned out to Armagh City for one season
Following his release by the Glens, McDonagh signed for Glenavon.
In August 2011, he signed for Monaghan United, again linking up with Roddy Collins.
On 18 June 2012, the club announced their withdrawal from the League of Ireland and all of their playing staff were released by the club McDonagh is currently operating in a centre back role under Longford manager Tony Cousins.