Simpkin was already contracted until the end of the 2022 season, however after playing just two games the Tigers have jumped to lock him up until the end of 2024.
The Tigers are hopeful Simpkin will be their No.9 far into the future, after loaned player Harry Grant opted for a return to Melbourne.
“I couldn’t be happier to be here at the club,” Simpkin said, following the signing.
“I’m really enjoying and excited by what we’re building at Wests Tigers and I want to be part of that long-term.
Following the recent recruitment of Jackson Hastings the Tigers are continuing to target the English league for talent, with Gildart in their sights.
Now the attention has been turned to acquiring the 24-year-old centre, who has expressed interest in entering the NRL before.
BREAKING: After week of turmoil the @WestsTigers are making enquiries about respected Wigan and Great Britain centre Oliver Gildart. Coach Michael Maguire is an admirer of his ability. @9NewsSyd @NRLonNine
— Danny Weidler (@Danny_Weidler) April 28, 2021
The Tigers will come up against St George Illawarra Dragons this Sunday in hope of claiming their second win of the season.