It’s a happy homecoming for the 23-year-old, who made his way up the junior ranks at the foot of the mountains before signing with the Roosters in 2017.
“I’m a Penrith junior who grew up in Glenmore Park dreaming of playing for the Panthers, so I’m very excited to come home,” O’Sullivan said.
“The opportunity to learn from the great coaches and quality halves at the club was one I simply couldn’t pass up.
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“I’m going to rip into pre-season and do everything I can to help Panthers achieve success again in 2022.”
O’Sullivan made his first grade debut for the Roosters in 2018 – scoring a controversial try in his only match for the tri-colours – before two seasons at Brisbane and a 2021 campaign with the Warriors.
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His signing will add some much-needed depth with Nathan Cleary and Jarome Luai likely to feature in State of Origin again this year and the sacking of bench utility Tyrone May.
“As a local junior who helped bring a national title to Penrith, we’re delighted to have Sean return to the club,” Panthers general manager Matt Cameron said.
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“His acquisition provides our NRL squad with vital halves depth ahead of the 2022 season.
“We’re confident Sean’s experiences as an NRL playmaker to this point have him well-equipped to fulfil an important role for the Panthers next season.”