Stephen O'Keefe is on Friday set to learn how serious his hamstring injury is and whether he'll play any further part in Australia's Test tour of Sri Lanka.
The left-arm finger spinner hurt his right hamstring while bowling his 17th over midway through the third day of the first Test in Kandy, forcing him from the field at Pallekele Stadium.
He didn't return as Australia's dominance waned.
Sri Lanka mounted a huge fightback, turning an 80-run deficit into a lead of 196 runs thanks to a brilliant 169 not out from Kusal Mendis.
They'll resume on the fourth day at 6-282.
Cricket Australia said the medical staff were assessing the extent of O'Keefe's strain.
It would be a big setback for O'Keefe if he's forced out of the tour after fighting his way back into Australia's XI to make his third Test appearance.
It would be a significant blow for Australia too as O'Keefe and Nathan Lyon are the only two specialists spinners in the 15-man squad.
The second Test starts next Thursday in Galle, which is regarded as the most spin-friendly of the Test venues where Australia would almost certainly include two tweakers.
"I feel sorry for Steve, he's one of my good mates," said Lyon.
"To lose someone like SOK (O'Keefe), who's a quality bowler, on a wicket like that with a couple spinning, a couple sliding on... he's very talented in these conditions.
"It was a big loss, but injuries happen in cricket."
If selectors need to seek a replacement, South Australian leg-spinner Adam Zampa or Victorian left-arm finger spinner Jon Holland would be in the frame.
Zampa is currently playing in the Caribbean Premier League while Holland is with the Australia A squad in Brisbane.
Ashton Agar is sidelined for four months due to shoulder surgery while leg-spinner Fawad Ahmed is another who would come into consideration.