Atiga was named in the Highlanders wider training squad after signing with Otago last year, and he has trained with the Highlanders for periods this season.
With outside backs James Paterson and Siale Piutau out for some time because of injuries picked up in the 20-7 loss to the Chiefs in Hamilton last Saturday, players will have to be called into the squad.
Atiga, a one-test All Black in 2003, has joined the squad and another new Otago signing, Buxton Popoali'i, is also expected to train with the team today.
Highlanders coach Jamie Joseph said he wanted to see how everyone trained today before deciding how many players he had to call up.
Winger Kade Poki was still a week-to-week proposition.
He has a damaged right knee which can sometimes swell up during the week. He was named to start against the Chiefs but did not make the trip north as the injury flared up.
Joseph said Poki needed an operation to clean up the knee but would have to wait until the end of the season.
Young winger Telusa Veainu will also come into calculations, though he has only made a couple of appearances off the bench so far this season.
Paterson is definitely gone for the season with a ruptured pectoral muscle.
Piutau had a scan on his leg yesterday. He has badly torn a groin muscle and Joseph said it was unclear how long he would be out.
He could recover reasonably quickly and return before the end of the season or he could be gone for the rest of the year.
Second five-eighth Shaun Treeby has been laid low by a medial ligament strain for nearly a month, and Joseph said he had run on a treadmill yesterday but he was unlikely to play on Friday night against the Hurricanes in Invercargill.
With the Highlanders having a bye after the Hurricanes game, Treeby was not likely to be back until May 28, when the Highlanders will take on the Lions at Carisbrook.
Joseph said the bye would come at a good time for his side with the injuries it has suffered.
"It will be just good to get through this week and then we have the bye where we can rest up a few bodies and then get a few players back," he said.
Loose forward Adam Thomson had popped some rib cartilage and was in some pain.
Thomson was due to play his 50th game for the Highlanders this week but would have to wait a little longer before reaching the mark.
Depending on progress, he could possibly be back for the Lions game.
Meanwhile, the Hurricanes will have to do without halfback Tyson Keats on Friday night in Invercargill after he was suspended for four weeks yesterday.
Keats was found guilty of dangerous play for a tip tackle on Blues halfback Alby Mathewson last Friday night.
