The Penrith Pqanthers are reportedly set to be without Brian To'o for the next month as he recovers from a hamstring injury sustained last weekend against the South Sydney Rabbitohs.

In what was a shock loss for the Panthers, To'o was taken from the field during the second half, with reports emerging a hamstring complaint was the reason.

That is now set to be confirmed by the club, with journalist Christian Nicolussi reporting on X (formerly known as Twitter), that the injury will see him ruled out for four weeks.

Ivan Cleary all but confirmed the news, per AAP.

“Nathan will be back, but ‘Bizza' (To'o) won't be. Hopefully Dyl will be,” the coach was quoted as saying.

“He (To'o) will be out for a few weeks.”

The club based at the foot of the mountains are yet to make official comment on To'o.

The Panthers have lost three matches straight, and To'o's barnstorming running game was set to be one of the keys as Ivan Cleary's side look to wrestle back momentum in the coming weeks with a returning Nathan Cleary and Dylan Edwards set to boost the side.

Those returns will shuffle Daine Laurie back to the bench and Brad Schendier out of the side, while Trent Toelau will also lose his spot at halfback.

Wither neither Laurie or Toelau likely to line up on the wing though, it likely means the Panthers will hand a recall to Casey McLean, who was a surprise axing ahead of the game against the Panthers.

He should slot straight back onto a wing, with Thomas Jenkins holding onto his spot in the centres and Paul Alamoti lining up on the wing once again.

A four-week lay-off means To'o misses games against the North Queensland Cowboys this weekend at home, then road trips to play the Dolphins and Sydney Roosters, as well as a home game against the Manly Sea Eagles before likely becoming a candidate to return in Round 9 against the Brisbane Broncos during Magic Round.