The Sydney Roosters are set to hand young prop Terrell May a debut in Saturday night's blockbuster against the Penrith Panthers at the Sydney Cricket Ground.

May has been among the best performing NSW Cup players throughout the first half of the season, and his debut has reportedly come with a three-year contract extension, as well as promotion to the top squad.

According to The Daily Telegraph, he signed the extension on Wednesday evening which will lock the talented middle forward in at Bondi until at least the end of the 2025 season.

Debuting against Penrith means May will debut against his brother Taylan, who has been a breakout star for Penrith on the wing this season.

It's understood the Roosters' young gun will come straight onto Trent Robinson's bench wearing jersey number 24 on Saturday evening, replacing either Daniel Suluka-Fifita or Fletcher Baker.

That news will be confirmed when teams are updated and cut to 19 players at 7:35pm (AEST) on Friday evening, 24 hours before kick-off, which should all but confirm the news of the youngsters debut.

May has been superb for the Roosters' feeder team the North Sydney Bears in the NSW Cup.

Playing eight games so far this season, he averages 170 metres per contest and has made 235 tackles with almost 97 per cent efficiency.

On top of his unbelievably high work rate, he also has 16 tackle busts and 15 offloads, as well as almost half of his metres coming as post-contact yardage.

The game comes on a Saturday which would feature both qualifying finals if the competition were to stop right now, with the first-placed Panthers playing the Roosters, and the second-placed Melbourne Storm taking on the third-placed North Queensland Cowboys in a game which would have been written off as a one-sided affair just weeks ago.

The Roosters will enter the game off last week's win over the Parramatta Eels, while the Panthers handed the Storm a beatdown during Magic Round.