But his ability to push through the pain barrier is legendary, and his experience will be vital against the Panthers.
Tuivasa-Sheck has an ankle sprain, and was hobbling as he went on stage at the Warriors end of season awards on Sunday, but has traditionally been a fast healer.
It will be a boost for the Auckland club to have their top 17, as most of their rivals deal with the absence of key players.
Probably the biggest hurdle for the Warriors will be overcoming a relative lack of finals experience.
Aside from prop Gavet, others set to line up in the playoffs for the first time are David Fusitu'a, Ken Maumalo and Solomone Kata plus interchange forwards Jazz Tevaga, Isaiah Papali'i and Bunty Afoa.
On the extended bench Mason Lino, Chris Satae and Karl Lawton also have never tasted September football.
However there are experienced comrades they can turn to.
Adam Blair, Tohu Harris, Tuivasa-Sheck and Gerard Beale have appeared in multiple finals campaigns and won premierships, while the 2011 grand final is one of Mannering's 10 playoff matches across his career.
Issac Luke also has considerable finals experience, though suspension ruled him out of the Rabbitohs' 2014 Grand final truimph.
The Panthers beat the Warriors 36-4 in July but the Warriors avenged that with their 36-16 victory at Mt Smart two weeks ago.
The two clubs have met in the play-offs only once before, the Panthers prevailing 28-20 in the preliminary final in 2003, before claiming the premiership a week later.
In 17 previous finals matches, the Warriors have won eight and lost nine while the Panthers have a 13-14 record including two grand final victories in 1991 and 2003.
WARRIORS v PENRITH PANTHERS
5.30pm, Saturday, September 8, 2018
ANZ Stadium, Sydney
VODAFONE WARRIORS
1 ROGER TUIVASA-SHECK (c)
2 DAVID FUSITU'A
3 PETA HIKU
4 SOLOMONE KATA
5 KEN MAUMALO
6 BLAKE GREEN
7 SHAUN JOHNSON
8 JAMES GAVET
9 ISSAC LUKE
10 AGNATIUS PAASI
11 ADAM BLAIR
12 TOHU HARRIS
13 SIMON MANNERING
Interchange:
14 JAZZ TEVAGA
15 ISAIAH PAPALI'I
16 BUNTY AFOA
17 GERARD BEALE
18 LEIVAHA PULU
20 MASON LINO
21 CHRIS SATAE
22 KARL LAWTON
HEAD COACH | STEPHEN KEARNEY