South Sydney have copped a blow on the eve of their NRL preliminary final with in-form centre Campbell Graham ruled out with a groin injury.

The 22-year-old was set for an electric battle with Penrith star Stephen Crichton, with at least one spot in the NSW Origin squad up for grabs between the pair.

However, on Friday morning Souths coach Wayne Bennett said Graham had been managing the injury for weeks and could not recover quickly enough for Saturday’s clash at ANZ Stadium.

“He hasn’t had enough time to get it right. He’s been managing it for about a month now but we’ve had a seven-day turn around and it’s not long enough this time,” Bennett said.

It opens the door for Jed Cartwright to move into the centres against his former club having been released by the Panthers mid-season.

The 23-year-old has played just six first grade games – only one of which was for Penrith in his NRL debut last season.

Cartwright has played Souths’ last five games from the interchange bench as either a second-rower or centre but Bennett is confident he could get the job done against his former club.

“He’s been playing a fair bit there with us since we brought him into first grade. He’s played there nearly every week at some stage or another, for varying amounts of time,” Bennett said.

“We’re very confident in him.

“He’s played a lot of centre in his football career, it’s not something he hasn’t played before.”

It will be a full-circle moment for Cartwright, who’s surname is synonymous with the Penrith club.

His father John won a premiership with the Panthers in 1991 and grandfather Merv was one of the club’s founding fathers.

“It’s a great name, his father was a wonderful player, I coached against his father and his grandfather was very instrumental in the building of the club there,” Bennett said.

“It’s 2020 now, he’s playing for Souths.”