The NSW Waratahs will be relying on debutant Mack Mason to guide them after Wallabies five-eighth Bernard Foley was ruled out of Sunday’s Super Rugby clash with the Crusaders.

The 21-year-old Mason comes in after Foley’s concussion symptoms returned following his comeback from the injury in last weekend’s win over the Melbourne Rebels.

In another major selection change, Rio Olympics rugby sevens star Cam Clark will start at fullback, with Israel Folau to move back into the centres after Rob Horne was ruled out with a hamstring injury.

NSW Waratahs: Cam Clark, Reece Robinson, Israel Folau, David Horwitz, Andrew Kellaway, Mack Mason, Jake Gordon, Jed Holloway, Michael Hooper, Ned Hanigan, Will Skelton, Dean Mumm, Sekope Kepu, Tolu Latu, Tom Robertson. Res: Damien Fitzpatrick, Paddy Ryan, David Lolohea, David McDuling, Michael Wells, Nick Phipps, Irae Simone, Taqele Naiyaravoro.