First first five-eighth Colin Slade broke his jaw in the first game of the pre-season and was ruled out for six weeks.
Now lock Tom Donnelly is out, also for six weeks, after a partial dislocation of the shoulder.
Donnelly, a key man for the All Blacks last year and one of the most experienced players in the Highlanders, lasted just 10 minutes in his first game of the season against the Chiefs last Saturday.
He fell awkwardly in a tackle and landed on his shoulder.
He left the field immediately and had a scan on Tuesday.
Although Donnelly was running freely at training on Tuesday, showing a fine turn of pace in the fitness drills, he did not do any contact work.
The scan revealed a partial dislocation of the shoulder, meaning he will not need an operation and will still be able to train.
A six-week layoff would see Donnelly back to play the Brumbies on April 1, as the Highlanders have a bye the preceding week.
In his absence, Josh Bekhuis and Jarrad Hoeata will be the likely starting locks, with Joe Tuineau another option.
News of Donnelly's injury was probably the last thing Highlanders coach Jamie Joseph wanted to hear.
The Highlanders are not a team littered with stars and experience, and to lose the likes of Slade and Donnelly for the start of the season is a huge blow.
As well as that experienced duo going down, there appears to be no chance of outside back Kurt Baker getting on the field this season.
Baker was picked by the Highlanders last season but almost immediately suffered a stress fracture to his back.
Baker, who had starred for the New Zealand Sevens side at the Delhi Commonwealth Games last year, was ordered to have three months of complete rest to help overcome the injury.
But a scan late last month revealed his back had not healed and Joseph confirmed yesterday he was gone for the season.
He will be replaced in the squad by Tasman outside back Kade Poki.
