The union has signed No8 Dylan Nel from Canterbury, prop Tom Hill, who is turning out for Taieri this year but played last year for Tasman, while forward Naulia Dawai is back from Ireland to join the squad again.
Otago Rugby Football Union general manager Richard Kinley said the three players had been signed for their experience and potential to fill spots in the squad.
Dawai (30) had played 27 games for Otago and left for Irish club side Connacht at the end of the 2016 season.
His two-year deal with the Irish club is up and the Fijian was keen to come back to Dunedin and play for Otago again.
Nel was born in South Africa and had moved to Christchurch to play club rugby in 2015. He played for West Coast in 2015 and then played one game for Canterbury in 2016 and four games last year.
With a crowded loose-forward cupboard in Canterbury, he has decided to try his luck in Dunedin and has signed a two-year deal with Otago.
Nel was club rugby player of the year in the Christchurch Metro competition last year for the Sumner club.
Kinley said Nel would come to Dunedin next month and play club rugby in Dunedin next year. He wanted to stay with his club in Christchurch for the rest of this year as he felt it had done a lot for him and he wished to show some loyalty.
Nel (25) is a strong running, ball-carrying forward, who was born in Durban. He came to New Zealand in 2015 after meeting former All Black No8 Murray Mexted in South Africa.
He was called into the Crusaders squad last year after Kieran Read broke his thumb, and also turned out for the Crusaders at this year’s tens event in Brisbane. He has not yet taken the field for the Crusaders.
Hill (22) is a loosehead prop who has impressed when playing for Taieri this season. He has an ability to get round the paddock and is a solid ball-carrier.
A former Nelson College pupil, he has played 10 games for Tasman but headed south in the off-season to help get a break for Otago.
With Craig Millar playing in Japan, Hill is likely to share the loosehead duties with Aki Seiuli.
Kinley said there were still places for local players.