Highlanders centre Tamati Ellison has been sidelined for most of the Super Rugby season after he had a shoulder operation during the off-season.

According to Fairfax Media, Ellison first injured his shoulder playing for Otago during last year's ITM Cup, and went under the knife after returning from the All Blacks end-of-year tour to Europe.

He underwent a scan which revealed a dislocation and a break at the top of the shoulder bone.

The 29-year-old's loss will be a major blow to the Highlanders, but he may yet still play for the Dunedin-based outfit if they qualify for the play-offs.

The Highlanders' have sufficient midfield options, including Ma'a Nonu, Shaun Treeby, Phil Burleigh and Jason Emery, in their squad which means they will not look to replace Ellison.

Rookie wing Declan O'Donnell will also miss most of the campaign with a shoulder injury and the Highlanders are likely to look for a replacement outside back.