Trbojevic will start the season as the Sea Eagles' No.1, with rising star Lehi Hopoate the first-choice winger for Saturday's clash with North Queensland.
One of the NRL's most lethal fullbacks, Trbojevic's long-term position has constantly been under the spotlight amid a string of injuries.
That debate intensified last season, when Hopoate emerged as a genuine future option for Manly at the back in a superb rookie year.
Seibold briefly toyed with playing Trbojevic at centre on return from a hamstring injury last July, a role the 28-year-old has starred in for NSW.
A future move to five-eighth has also been floated when Daly Cherry-Evans retires, as part of a switch that would see Hopoate wear No.1.
But after finishing fourth in the Dally M race last year and playing his most games since 2018, Trbojevic said he had not even contemplated a future position.
"It's not really something I have even thought about," Trbojevic said.
"I have obviously played centre before so I know what that is like, I have never played five-eighth in however long I have been playing footy.
"I feel like the way I finished last year at fullback is some of the best footy I have played.
"I get a lot of confidence from that, and I really enjoyed the back end of that and hopefully I can start the year in same way."
Trbojevic also admitted at times he found the constant debate around his decision frustrating, insistent any decision on a future position need not be rushed.
Manly have won 36 of 55 games Trbojevic has started at fullback since the start of his 2021 Dally M year, scoring 57 tries and setting up 59 in that time.
Their record without him during that period is 15 wins from 46 matches.
Hopoate played No.1 as a junior, but the newly re-signed 20-year-old has also made clear he is happy to play on the wing while learning from Trbojevic.
"I've got a long-term plan for Lehi, but if you look at all the really elite fullbacks ... it's not an unusual journey Lehi is undertaking," Seibold said.Â
"Turbo came through when Brett Stewart was fullback, played on the wing and played centre.
"Roger Tuivasa-Sheck came through when (Anthony) Minichiello was fullback, played on the wing.
"Minichiello came through when Luke Phillips was fullback at the Roosters, played wing.
"If Turbo isn't the best fullback in the comp then he is definitely in the best two. He's probably in the top three players overall. He's a great person to mentor people.
"Lehi is only 20, he is right at the very beginning. He will eventually play fullback, but he is earning his stripes and will develop. What better person to do that under."
14°C