He was defense coach in 2013 and 2017.
Ireland head coach Andy Farrell is set to play a part in the British and Irish Lions' Tour of South Africa.
The Irish Times report that Farrell may join up with Warren Gatland's coaching staff after the home tests against Japan and the USA in early July.
Farrell was defence coach for the Lions for the 2013 and 2017 Tours.
The Lions play the Springboks in the first of three test matches on Saturday July 24th.