It was expected that he would return to resume his second row partnership with Paul O'Connell against France this weekend, but despite training with the squad on Tuesday ahead of the team announcement, the troublesome left knee forced the big Corkman out of the reckoning..
In the circumstances, O'Callaghan, lauded by his team-mates for his dedication and professionalism, has opted to continue his rehabilitation abroad with the Munster squad.
His decision to travel raises the possibility that he could appear next in the Munster jersey against Edinburgh in Friday week's Magners League encounter at Musgrave Park.
The Munster players not involved with Ireland this weekend or the province's British & Irish Cup game against Nottingham have flown out for a warm weather training campe in Lanzarote.
It is the second successive year that head coach Tony McGahan has taken his players to Club La Santa, which is located on the north west coast of Lanzarote, for a week of intensive training.
Apart from O'Callaghan, there are 26 other players travelling to Spain and they will arrive home next Wednesday, in time for the Edinburgh game. Doug Howlett, Tony Buckley and Denis Hurley are flying south on Friday.
MUNSTER Training Squad: Cathal Sheridan (UL Bohemians), Dave Ryan, Jeremy Manning, Peter Stringer, Jean de Villiers, Paul Warwick, Billy Holland, Ian Dowling, Lifeimi Mafi, Damien Varley, Julien Brugnaut, Tommy O'Donnell, Duncan Williams, Scott Deasy, Tom Gleeson, James Coughlan, Marcus Horan, Alan Quinlan, Denis Fogarty, Denis Leamy, Doug Howlett, Denis Hurley, Nick Williams, Mick O'Driscoll, Niall Ronan, Tony Buckley, Donncha O'Callaghan (rehab).