Simon Yates' knee injury threatens to derail Mitchelton-Scott teammate Daryl Impey's bid for an unprecedented third straight Tour Down Under win.
The English star was caught up in a huge crash less than 2km out from the finish on the uphill run into Stirling on Wednesday's stage two.
It left him nursing a nasty gash on his left knee as he got up and struggled to reach the finish line.
Yates did not lose time, however, he is in doubt to start on stage three and will be assessed by team medical staff overnight.
"He banged it pretty hard," Mitchelton-Scott sports director Matt White said.
"He's taken a fair bit of skin off and he could hardly pedal to the finish line.
"Knees are funny things, you obviously don't function too well without them, but they can also free up quite quick or go the other way.
"Time will tell."
Impey finished second behind Australian star Caleb Ewan (Lotto-Soudal) on stage two and trails the ochre jersey wearer by one second.
Stage one winner Sam Bennett is tied with Ewan on time, leaving Impey in third place overall.
Stage three up to Paracombe on Thursday is one for the climbers - which does not suit Impey - and Yates had been slated to take on the likes of Richie Porte (Trek-Segafredo).
Porte, the 2017 overall winner, has finished runner-up to Impey for the last two years and looms as a big threat again this year.
"Daryl is in pretty good shape so it (Yates' injury) is not going to change our tactics, it might just take one option out of our deck of cards," White said.
"That was the plan (to use Yates to try to deny Porte stage victory), we still might be able to do that tomorrow or not, we'll see."
Impey picked up another six seconds bonus time on the stage two finish line - making it nine seconds in total - but faces a tough ask up the famed Paracombe climb.
"It's going to be a tough day," Impey said.
"It's pretty much the queen stage, it's a stage where you can lose pretty much nine seconds or 10 seconds.
"It's about going to the line and limiting the loss.
"It's the same finish that it was two years ago when Richie (Porte) annihilated everyone, but I'm in much better shape than I was back last time I did it.
"I'll give it everything I can."
Australian Associated Press