Dom fully grasped his First Team chances in 2014, recording 11 tries in 14 appearances.
The pacey 21 year-old winger made his debut in 2013 after being rewarded with a full-time contract with the First Team squad earlier that year.
Manfredi has since made significant progress over the past 12 months and deputised well for Josh Charnley in parts of the season. He also spent part of the season on loan at Salford.
He is a hard-working individual with a real sense of determination who has also bulked up ahead of the new campaign.
Manfredi joined the Club from Leigh Miners at the age of 14 and progressed well through the Scholarship and Academy set up.