Anthony Seibold has declared the Tom Trbojevic centre experiment over for the foreseeable future with the superstar fullback to remain at No.1 long term.
The Dally M medallist played 83 minutes wearing No.3 for the Sea Eagles in their golden-point win over North Queensland last time out - his first appearance since injuring a troublesome hamstring in May.
Coach Seibold had initially planned to ease Trbojevic back into the line-up by starting him in the centres - where GPS data showed acceleration was less intense than at fullback - but a knee injury to stand-in No.1 Toula Koula scuppered his plans.
"With him being out, we felt as though now it's best to get Turbo (Trbojevic) back to fullback," Seibold said on Saturday.
Koula had impressed as deputy and was among Manly's best against the Cowboys, running for 289 metres and busting seven tackles, setting up a second-half try with a break down field.
With the 21-year-old expected to be out for up to six weeks, Seibold resisted the temptation to move teenage prospect Lehi Hopoate to No.1.
"(Trbojevic) will be fullback for this next period of time," Seibold said.
"I've always said Turbo's our best fullback, I've been adamant about that."
The Sea Eagles are missing a wealth of experience, with talismanic No.7 Daly Cherry-Evans (State of Origin duty) and hooker Lachlan Croker (neck) also unavailable against Newcastle.
Without Trbojevic's switch, five-eighth Luke Brooks would have been the only first-choice player in Manly's spine.
Trbojevic, a local junior, will captain the club for the first time, his experience and communication skills key to his return to fullback.
Seibold said his defensive line organisation was as good as any No.1, even up there with Melbourne Storm legend Billy Slater.
"We've got a group (Cherry-Evans, Trbojevic, brother Jake Trbojevic) and myself, we collaborate on how we want to do things and Turbo has been a big part of that," Seibold said.
"It's a great achievement for Turbo personally, for his family.
"It's a really good recognition of Turbo and the influence he's got on the group."
Skilful halfback Jamie Humphreys will fill Cherry-Evans' vacant No.7 jersey after the 22-year-old impressed in reserve grade since being switched from hooker.
"We don't need him to be Chez (Cherry-Evans)," Seibold said.
"Brooksy needs to stand up there. Him and Turbo will organise our attack. Jamie just needs to get his D (defence) right, help with our end of sets because he's got a fantastic kicking game and then just organise his edge on attack."