Thanasi Kokkinakis has withdrawn from his hometown Adelaide International with a shoulder injury in a fresh blow to his Australian Open hopes.
The 2022 champion was due to play second seed Sebastian Korda on Thursday night for a place in the final four, but was a late withdrawal citing a right shoulder complaint.
His injury-enforced exit followed a three-hour slugfest against Tomas Martin Etcheverry on Wednesday, when the injury appeared to be giving the world No.77 grief.
Kokkinakis also withdrew from last week's Brisbane International with a hip injury, his latest setback an untimely one with the Australian Open due to begin on Sunday.
Earlier on Thursday, American Tommy Paul signalled his intent to bludgeon his way into the top 10.
Paul ended the Adelaide International dream for Australia's Rinky Hijikata with a clinical 6-3 6-4 victory at Memorial Drive.
And the tournament's top seed did so while testing out tactics he hopes will lift his world ranking from No.12.
"We wanted to sharpen the things that I've done well in the past and then also trying to add some ball speed on my shots," Paul said.
"You look at the top guys and they're paying the ball out harder than me, to be quite blunt.
"I'm trying to pick up the ball speed.
"Today I did a decent job of it, and it's about picking the times of when you want to do it ... I missed a few more backhanders than I would have liked, but it was because I was trying to lean into (them) a little more, hit them a little harder."
The 27-year-old from Voorhees in New Jersey advanced to a semi-final against Canadian Felix Auger-Aliassime, who defeated American Marcos Giron 7-6 (7-3) 6-3.
Paul hopes his focus of adding power will pay off at the Australian Open and edge him into the world's top 10.
"Whenever you come here, you're coming off of a long training block - there's pros and cons to it," he said.
"I'm not exactly match-trained - more like physically in great shape, but match conditioning is different.
"And getting your mind ready for matches like this and matches like the Australian Open is important.
"That's what this week is all about. Obviously, everyone wants to do really well here, but the main goal when coming to Australia is to do well in the Aussie Open."
Korda will face in-form Miomir Kecmanovic in the other semi-final after the Serb blitzed France's Benjamin Bonzi 6-2 6-3.
