Tom Trbojevic insists there are no ongoing concerns over his fitness after he helped Anthony Seibold's era at Manly get off to a winning start with a 31-6 defeat of Canterbury.

Trbojevic scored a try and had a hand in two others as Manly dominated the game at 4 Pines Park in his first appearance since dislocating his shoulder last May.

Halfback Daly Cherry-Evans bagged the first hat-trick of his career with a last-minute intercept and late field goal, benefiting from Manly dominating the inexperienced Bulldogs pack.

But eyebrows were raised when Trbojevic opted against breaking into full flight when put into space during the second half, before later leaving the field with 15 minutes left.

Trbojevic suffered his fifth hamstring setback in five years during the pre-season, prompting a $50,000 trip to the USA to try and remedy the situation.

"My calf was cramping up a bit, but I can definitely open up," Trbojevic said after the game.

"It's hard to prepare to play footy again, I haven't played for 10 months. It's hot out there, and that just happens. There's no issue.

"It was a very nervous week, (after) not playing for a while. I just wanted to get back out there."

Seibold insisted afterwards he had no plans to manage the fullback through the start of the season.

"It wasn't because we were ahead or anything like that," Seibold said.

"The message came off the touchline Tom was starting to cramp. But he had some pickle-juice and was able to get back on when Lachlan Croker came off (for an HIA)."

Trbojevic appeared as if his timing was slightly out at times, but offered a reminder of why he is regarded as one of the NRL's best.

He scored Manly's first when he toed ahead a Cherry-Evans grubber kick, and the pair combined again in the second half for the halfback to score after a Taniela Paseka bust.

The game was not without controversy, with the Sea Eagles scoring two tries while Kyle Flanagan was sin-binned.

With scores locked at 6-6 shortly before halftime, Flanagan was punished by the bunker for lightly pushing Trbojevic in pursuit of a grubber kick.

Manly scored down Flanagan's left edge minutes later, when Trbojevic and Kelma Tuilagi put winger Reuben Garrick over untouched.

In reality though, Manly were the better team throughout as they ended the seven-match losing streak that snuffed out their 2022 campaign after the Pride Jersey saga.

Canterbury looked like a side with eight new faces from last year under new coach Cameron Ciraldo.

Matt Burton's bombs were dangerous when on target, but he and Viliame Kikau both put kicks out on the full, while another kick off from the five-eighth went astray.

Kikau was well contained, with Max King the sole Bulldogs forward to exceed 80 run metres.

The Bulldogs' one try came when hooker Reed Mahoney collected his own grubber kick off the posts and was ruled to have got the ball to ground without dropping it.

"We lacked cohesion at times around that area and a lot of other areas as well," Ciraldo said.

"We're a new team ... We're going to be better every week."