Blake Taaffe, who came in at the 11th hour in 2021 to help the Rabbitohs to a grand final, has appeared to have injured himself at training and could be doubtful for the club's season debut against the Broncos tomorrow night.

According to Christian Nicolussi of the Sydney Morning Herald, Taaffe failed to finish training this morning after it appears he rolled his ankle, leaving a "decent divot" in the ground.

Taaffe, who played some of his junior rugby league with the local La Perouse United, stepped in at fullback for the suspended Latrell Mitchell at the end of the 2021 season.

The young fullback is heralded within the club and is pitched to be a hallmark piece of the Rabbitohs' future.

Taaffe was expected to be playing number one this Friday night, with Mitchell still out due to suspension until Round 2.

If Taaffe is unable to play against the Broncos this will cause a huge shift in the team's backline and potentially the halves. While South's coach Jason Demetriou has told Fox Sports that he pulled up okay following the roll, he has a plan should he be ruled out.

The obvious decision is to put Alex Johnston back at fullback, a position he's certainly comfortable with, and pull Josh Mansour from the extended bench into Johnston's spot at the wing.

SYDNEY, AUSTRALIA - AUGUST 18: Alex Johnston of the Rabbitohs breaks away to score a try during the round 24 NRL match between the South Sydney Rabbitohs and the New Zealand Warriors at ANZ Stadium on August 18, 2017 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

However, the side could also put Cody Walker at fullback, and shift Cameron Murray into the five-eighth position alongside rookie Lachlan Ilias. This change is a little more unlikely, as coach Jason Demetriou wouldn't want to put more pressure on Ilias heading into Friday, but it leaves Johnston at a position where he does his most damage.