Ronan started the game at Murrayfield while Horan and O'Driscoll were introduced as second half replacements. They are joined for the trip to France by their fellow Rugby World Cup hopefuls, Damien Varley and Peter Stringer.
Also included in the 31-man squad are newcomers BJ Botha and Ian Keatley along with Under-20 International JJ Hanrahan and former Munster squad member Gerry Hurley, who provides cover at scrum half in place of the Ireland-tied Tomas O'Leary and Conor Murray.
Tony McGahan's men are due to play French club side la Rochelle at the 12,352-capacity Stade Marcel-Deflandre on Friday night (kick-off 7pm local time).
MUNSTER Squad (Pre-Season Camp) - Backs (13): Denis Hurley, Simon Zebo, Doug Howlett, Johne Murphy, Scott Deasy, JJ Hanrahan, Danny Barnes, Lifeimi Mafi, Ian Keatley, Declan Cusack, Gerry Hurley, Peter Stringer, Duncan Williams.
Forwards (18): Darragh Hurley, Wian du Preez, BJ Botha, Marcus Horan, Peter Borlase, Stephen Archer, Damien Varley, Denis Fogarty, Mike Sherry, Mick O'Driscoll, Ian Nagle, David O'Callaghan, Paddy Butler, Billy Holland, Niall Ronan, James Coughlan, Tommy O'Donnell, Peter O'Mahony.