Dean Matterson, younger brother of Parramatta forward Ryan, is set to join the Sea Eagles in 2023 as he looks to step out of his brother's shadow.

The 24 year-old lock won the Mounties Player of the Year award in the NSW Cup after a stellar season, attracting interest from a number of clubs before landing on the Sea Eagles.

While the club already has an established lock in Jake Trbojevic, losing the likes of Andrew Davey and Martin Taupau are big blows to Manly's forward pack, while highly-rated youngster Josh Schuster moves out of the forwards and into the vacant No. 6 jersey.

Like his brother, Dean is a former five-eighth that's moulded into the ball-playing lock you see today, and with a hulking frame, he can create real havoc for defenders when he takes the ball to the line.

Wide World of Sports spoke to Dean's manager, Gavin Orr, before the uncapped forward makes the move to the Northern Beaches.

"Dean is around 100 kilos and has good ball skills, much like Ryan," his manager Gavin Orr told WWOS.

"He was offered longer deals elsewhere but decided to back himself and sign for just the one season at Manly.

"Hopefully he can really establish himself and then get himself a better deal for the future.

"He was impressed by Manly and thought while it would have been good to play in the same system as Ryan at the Eels, it's best to go it on his own at Manly."

Dean will be aiming to put the Matterson name back into a positive light after Ryan was bashed pillar to post for accepting a three-game ban instead of copping a $4,000 fine.