The extent of the injury will be known when Sullivan has surgery on Thursday but there’s an expectation he’ll be out of rugby for a minimum of one month.
Sullivan said he was gutted to receive the news but is remaining positive.
“It was a tough night when I did it and knowing I would be sitting down for a wee while again,” said Sullivan.
“Having just come back from injury, I was firing and ready to go but I know this is all part of sport and I’ll get this surgery done, do my rehab then be back on the park as soon as I can.”
“I also want to thank everyone for their kind messages and well wishes, it means a lot and I hope everyone can get in behind the Blues boys for this exciting part of the season,” he said.
The Blues’ next Super Rugby Pacific home game is against the Highlanders this Saturday at 7.05pm at Eden Park.