Sironen was named 18th man for last week's encounter with Cronulla, and ultimately managed 12 minutes of game time in that contest after Euan Aitken was taken off with concussion in the 53rd minute.
But the injury is still troubling him, and it is expected to leave him out of the side for up to three weeks, with a return likely in Round 12 against Newcastle on May 28.
Several other Warriors stars are also nursing injuries, and are aiming to return to the side in the coming weeks.
Jesse Arthars is in line to be available in Round 12 too, as the centre recovers from an AC shoulder injury.
Chanel Harris-Tavita is aiming to return to the side in Round 11 (vs St George Illawarra) after undergoing surgery for a ruptured testicle.
Meanwhile, Josh Curran is showing promising signs, making solid progress with his MCL knee injury and looking to build into field training next week.
— Vodafone Warriors (@NZWarriors) May 10, 2022
The Warriors take on the South Sydney Rabbitohs this Saturday afternoon (3:00pm AEST).