With his team already reeling from the third serious injury sustained by one of their halfbacks this year, fullback Nicoll-Klokstad was handed a grade-three dangerous contact charge on Sunday.
The charge is the harshest that can be handed down by the match review committee for a hip-drop tackle without referring the player straight to the judiciary.
The committee chose to do that previously this year, when St George Illawarra lock Ryan Couchman was suspended for four games for the tackle that ruptured J'maine Hopgood's ACL.
Walsh underwent scans on Sunday afternoon, and is now expected to miss eight weeks with a high-grade syndesmosis injury that now threatens his World Cup.
Nicoll-Klokstad will be free to face Manly in the final round of the regular season if he enters a guilty plea, while he would miss that game if he fought the charge and lost.
While Nicoll-Klokstad is free to play in the finals, his suspension looms as a threat to the Warriors' top-two chances.
The Auckland-based club are third on the ladder with three rounds to play, but only behind second-placed Penrith on for-and-against.
A top-two finish would offer a massive advantage come finals, with the prospect of not leaving New Zealand until grand final week if they win through.
Taine Tuaupiki has played 15 games at fullback this year for the Warriors, with Nicoll-Klokstad having been sidelined by a neck injury before spending time in the outside backs.
While Tuaupiki is expected to slot into fullback against South Sydney next week, the Warriors have bigger questions around their halves.
Metcalf is set to join fellow halves Te Maire Martin and Tanah Boyd on the sidelines for the run home, after he limped from the field with a right hamstring injury after taking a kick at goal on Saturday night.
Martin is due to return from his own hamstring injury just before finals, after he became the man to replace Tanah Boyd when he ruptured his ACL in May.
Metcalf had then impressed when given the chance last week, but his hopes of guiding the Warriors to a premiership before moving to the Dragons appear sunk after this latest blow.
In the short term the Warriors could turn to Luke Hanson for his second NRL game next week, or throw Jett Cleary an NRL debut against South Sydney.
Cleary has recently sought a release out of the club, keen for a move back to Penrith next year for his father Ivan's last year in charge of the Panthers.
Elsewhere North Queensland second-rower Heilum Luki has avoided a ban for a high tackle against Parramatta, instead able to accept a $3000 fine.
The Warriors also have two players facing fines, with forwards Tanner Stowers-Smith and Jacob Laban earning the ire of the match review committee.
