Magpies assistant coach Danny Lee said the team's physio Mark Nicol has been in contact with the Chiefs medical staff and learned the surgery option taken was the best for the longevity of Allardice's career.
"The injury is tough on Michael because he has been playing some good rugby. He is in our senior players bracket and the last thing he wants to do is miss the Mitre 10 Cup. However you never know, his recovery could go well once he works alongside Mark and our trainer [Luke Stephenson] and we could see him in action towards the end of the season."
"There will be opportunities for regular starts for the likes of Geoff, Junior [Waqa] and Trent. They've all been involved with our team and know our systems," Lee said.
Meanwhile Allardice's Napier Pirate Rugby and Sports clubmate and former Magpies halfback Michael Ruru won the player of the tournament award after helping his Western Force team win the World Club 10s in Mauritius last weekend. The Western Force side, which was made up mainly of premier club players, beat a Brumbies team dominated by Super players 7-0 in the final.
Ruru, 24, converted the lone second-half try by winger Brad Lacey. Ruru has been Perth-based since playing for the Magpies in 2012.
He hoped the award will enhance his chances of securing a professional contract.
"I'd love to take the next step to play rugby professionally for a living and give back to the community, but if it comes it comes, if it doesn't it doesn't," he said.
Ruru's younger brother Jonathan, who played one game for the Magpies last year, is playing club rugby in Dunedin with the aim of making the Otago Mitre 10 Cup team.