Tuitavake, 30, was to play in Bulls warm-up games over the weekend but struck visa issues and was unable to board his flight from New Zealand.
Tuitavake broke his arm while playing England with Tonga during last year's Rugby World Cup in Japan, his only appearance at the tournament.
The younger brother of All Black Anthony Tuitavake, he made his debut for North Harbour in first-class rugby in 2008 and went on to make 76 appearances for the side before his last game in 2014.
He also had a season with the Crusaders in 2014 in Super Rugby.
Tuitavake had a season with Agen in France in 2012-13 and from 2016 he played with Northampton in England's Premiership. He was released by the club at the end of the 2018-19 season.
He made his Test debut for Tonga in 2016 and has played 14 Tests.
Bulls chief executive Alfons Meyer said due to his visa issues Tuitavake stayed in New Zealand .
"We're in daily contact with his agent. We're eagerly awaiting his visa to be approved," he said.
Tuitavake has signed a two-year deal with the Bulls.
Meanwhile, the Sharks Super Rugby squad had a mixed day of warm-up games on Friday.
Their more experienced side beat the Russian Test side 64-14 while their other combination lost to NEW-Pukke 26-31.
The Sharks have another game against Russia on Friday and then play the Stormers in Johannesburg on Sunday, January 19 in their last warm-up game before the Super Rugby season starts.