Mannering's switch back to the edge should also revitalise him, after a few years at lock with a seemingly endless defensive workload.
Mannering replaces Leivaha Pulu, who appeared in the first six matches of the season but was forced off with a foot injury midway through the first half last Saturday.
Warriors centre Solomone Kata has been selected at left centre, but there is some doubt he will play. He was forced off late in the Broncos game with an ankle injury, and the early signs weren't good, as he was in a moon boot after the match. But he took part in training yesterday, and faces another session tomorrow before coach Stephen Kearney will make his decision.
"Sol [Kata] is a chance of playing on Friday," said Kearney. "He had a run today and we need to see how he pulls up today and tomorrow, so he's a chance."
If Kata is deemed unfit to start, Kearney confirmed that Anthony Gelling will take his place.
Filling Mannering's spot on the interchange is 44-game front rower Albert Vete. He has been a regular over the last three seasons but has been consigned to reserve grade so far this year. He helped his cause with a standout display against the Sea Eagles last Saturday, with 174 metres from 15 runs including 55 post-contact metres with six tackle breaks.
Aside from Vete, the other players on the extended eight-man bench are utility Jazz Tevaga, prop Sam Lisone, centre Gelling, prop Chris Satae, halfback Mason Lino, second rower Isaiah Papali'i and wing Charnze Nicoll-Klokstad.
After six consecutive Saturday matches, this week's encounter with the Dragons is the first of eight Friday night matches the Warriors play this season.
The occasion coincides with hooker Issac Luke's 50th appearance for the club, his 237th overall, while halfback Shaun Johnson will play his 149th match leaving him in line for his 150-game milestone in the traditional Anzac Day contest against the Melbourne Storm next Wednesday.
The Dragons are unbeaten this season.
The last time the Warriors and the Dragons met at Mt Smart Stadium in 2016, the home side won 26-10. It remains only the fifth time the Warriors have beaten St George Illawarra in 26 encounters.