His injury is the worst in a growing casualty list for the Chiefs as they began their title defence against the Crusaders with a defiant 18-10 win.
Muliaina lasted 37 minutes before heading for the sideline after damaging the same elbow he had surgery on during his last contract in Japan.
He went in for surgery yesterday with fears he would be off the playing roster for several months, adding to an injury list affecting half the squad.
A number will return to training tomorrow but about 10 players will still not be available for Saturday's home game against the Highlanders.
Joining Muliaina on the casualty list from game one are No8 Kane Thompson, who damaged his groin, tight five forwards Brodie Retallick and Ben Afeaki, who need to pass concussion tests, and halfback Augustine Pulu, who twisted his knee.
Flanker Tevita Koloamatangi suffered badly from cramp and Andrew Horrell, Charlie Ngatai and Tim Nanai-Williams all suffered some strains but are all expected to recover.
"It was a pretty brutal game," coach Dave Rennie said, "but I thought we showed an amazing amount of character."
He thought the Chiefs had "stressed" the Crusaders a lot, even though the hosts had a hefty territory and possession advantage.
The Chiefs put a lot of emphasis on character in their squad and that was a crucial part in their player recruitment policies and training methods. Seven of the Chiefs played their first game of Super rugby against the Crusaders and really fronted.
"It is really exciting and we have got some firepower still to come back," Rennie said.
That group includes Tawera Kerr-Barlow, Sam Cane, Tanerau Latimer, Mahonri Schwalger, Robbie Robinson, Tom Marshall, Bundee Aki and Gareth Anscombe.
Several would be borderline ready this weekend but it might be more prudent to get them through training then a bye week to be ready for the side's trip to South Africa.
Co-captain Aaron Cruden was in great form directing the side, making all 15 tackles and coming within a tick of a great team try. He had battled with his goal kicking pre-match and there was some variation with the Gilbert match balls used in New Zealand, Australia and South Africa.
New centre Robbie Fruean has wound up his fitness, his involvement and tightened his defence, which the Chiefs used to target when he was at the Crusaders. He has fitted into the squad well, was casual off the track but a potent force on it.
Another signing, loosehead prop Jamie Mackintosh, has also made shifts in his game since coming north. He has tightened his technique at the scrum and was using better technique when he carried the ball into contact.
