Ronan O'Gara and Tony Buckley were there also, but unlike O'Callaghan, they took a full part in training. With the international trio back on board, Munster will look to continue their impressive home form in the Magners League this weekend.
Flanker Billy Holland, who has impressed in red in recent weeks, sat out the session having twisted a knee in the game against Scarlets last Thursday.
Meanwhile, the news on scrum half Duncan Williams (ankle) is also good in that he sustained bruising and no break when being forced off in the closing stages of the 23-17 win over the Scarlets.
MUNSTER Squad (v Glasgow Warriors) - Backs (12): Duncan Williams, Conor Murray, Peter Stringer, Paul Warwick, Ronan O'Gara, Scott Deasy, Jean de Villiers, Lifeimi Mafi, Tom Gleeson, Ian Dowling, Doug Howlett, Denis Hurley.
Forwards (14): Marcus Horan, Tony Buckley, Dave Ryan, Denis Fogarty, Damien Varley, Julien Brugnaut, Mick O'Driscoll, Donncha O'Callaghan, Billy Holland, Niall Ronan, Alan Quinlan, Tommy O'Donnell, Nick Williams, James Coughlan.