Daryl Gibson fears Kurtley Beale has played his last game for Waratahs after the Wasps-bound utility back suffered what is feared to be a serious knee injury in the 31-8 hammering of Bulls on Saturday.
Ambitious Wasps on Friday confirmed that Beale will move to the Premiership ahead of the 2016-17 in a deal reportedly worth £1.5million.
Beale spoke of his excitement over the move to England, but the Australia international could now be facing a lengthy spell on the sidelines after he was carried off with what was described as a "significant" knee injury.
Waratahs coach Gibson thinks the 27-year-old, who first joined Waratahs at the age of 16, is "very unlikely" to play for the franchise again after going down in the first minute at Allianz Stadium.
He added: "At this part of the year, particularly with the sparkling form he's in, he's certainly a big part of our attack and to have that taken away [is hard],
"I'm disappointed to see him go [to Wasps], but I can fully understand his reasons and I think when a player leaves here we spoke at length today about making sure he signs off in the correct way,
"The disappointing thing for me with his injury is that he won't have the opportunity to do that."
Beale, who looks set to miss the Test series against England, was taken to hospital and an update on the extent of his injury is expected on Sunday.