All Blacks halfback Justin Marshall has been switched from the bench to a starting role with the Crusaders because medical staff raised doubts about his recovery from injury if he began the game on the sidelines.

On the comeback trail after a muscle injury in his foot, Marshall (pictured) will start the game against the Waratahs on Thursday night because otherwise the stop-start nature of coming on and off the bench could see him re-injure the muscle.

"Our medical staff thought it would be better for him to warm up and play, as opposed to potentially warm up and cool down often," coach Robbie Deans said.

Ben Hurst makes way after a solid performance against the Reds last weekend, with vice-captain Aaron Mauger also coming in at centre for Daryl Gibson and All Black Greg Somerville replacing NZ teammate David Hewett at tighthead prop.

Despite the changes though, Deans says all 26 members of the squad will be given time on the field during the match.

Teams:

Canterbury Crusaders: Leon MacDonald, Joe Maddock, Mark Robinson, Orene Ai'i, Aaron Mauger, Andrew Mehrtens, Justin Marshall, Sam Broomhall, Johnny Leo'o, Chris Jack, Bradley Mika, Reuben Thorne (capt), Greg Somerville, Mark Hammett, Nick White. Substitutes: Caleb Ralph, Nathan Mauger, Daryl Gibson, Ben Hurst, Scott Robertson, Richard McCaw, Matt Mustchin, Norm Maxwell, David Hewett, Greg Feek, Corey Flynn.

NSW Waratahs: Mat Rogers, Marc Stcherbina, Matthew Burke (capt), Nathan Grey, Manuel Edmonds, Chris Whitaker, David Lyons, Des Tuivaii, Van Humphries, Tom Bowman, Omar Hassanein, Rod Moore, Brendan Cannon, Matt Dunning. Substituts: Duncan McRae, Luke Inman, Francis Cullimore, Huia Edmonds, Patricio Noriega, Steve Talbot, Phil Waugh, Tim Clark.