When Des Hasler eventually puts pen to paper to extend his reign as the Sea Eagles' head coach, he stands to break a 21-year-old record.

According to NRL.com reporter Dan Walsh, when the 59-year-old agrees to terms in the new year, he appears certain to surpass Bob Fulton's 307 games in charge of Manly and become the club's longest-serving coach.

Hasler's current tally of 252 games in the Brookvale hot seat is still well shy of his former coach's total, but with a contract until the end of next season and an extension imminent, the honour boards in the Jane Try Stand look likely to be updated.

Although his contract is almost certain to be lengthened, Walsh remains uncertain whether it will be for a single or pair of seasons.

Should the former be the case, then Hasler will almost certainly have passed the 300 game mark, but if an agreement until the end of 2023 is inked, then Fulton's tally will be in his rearview mirror.

With the Sea Eagles missing the finals in 2020, Hasler has shuffled his deck in an attempt to win his first Premiership since 2011.

Despite losing Addin Fonua-Blake to the Warriors in the off-season, Manly has bolstered numerous positions on the park with the additions of Jason Saab, Christian Tuipolotu, Josh Aloiai and the return of prodigal son, Kieran Foran.

Foran's form may have forsaken him in his five years spent away from Brookvale, however, Hasler will be hopeful that when paired again with Daly Cherry-Evans, the duo can turn back time and resurrect Manly's fortunes.

Another thorn in Hasler's side has been Tom Trbojevic's inability to avoid injury.

According to Walsh, 'Tommy Turbo' has managed just 19 games for the Maroon and Whites across the past two seasons.

On-field performances will factor into the length of Hasler's tenure on the Northern Beaches.

Still, should the aforementioned quartet of recruits hit the ground running and Tom Trbojevic remains on the park, then Hasler appears certain to overtake his former mentor.