Souths coach Michael Maguire has delivered a blunt ultimatum to George Burgess - fire up or flounder in reserve grade.

The premiership-winning prop has been left out of Maguire's 17 for Friday's NRL season opener against the Wests Tigers at ANZ Stadium.

On the outer: George Burgess failed to impress Michael Maguire during the pre-season. Credit:Getty Images

Burgess has fallen hard since establishing himself as one of the game's best big men during the Bunnies' drive to the 2014 title.

Maguire has shown he has no regard for reputation by naming 20-year-old Zane Musgrove to start in Burgess's place for round one.