Dayana Yastremska's coach Sascha Bajin blasted her critics Thursday, saying he wanted to "shut some people up" after former world number one Caroline Wozniacki accused the Ukrainian of faking an injury.

The 19-year-old was one game away from defeat against the former world number one at the Australian Open on Wednesday when she called for a medical timeout, and a trainer came on court to strap her left thigh.

She managed to save a handful of match points on resumption before the Dane wrapped up a tough 7-5, 7-5 victory.

Asked about the timeout in her post-match press conference, Wozniacki replied: "Obviously she tried to break my rhythm. And at 5-4 I don't think there is anything wrong. She was running just fine.

"So that's a trick that she's done before, and I knew that it was coming," she added.

Ukraine's Dayana Yastremska receiving medical treatment during her Australian Open clash with Caroline Wozniacki
Ukraine's Dayana Yastremska receiving medical treatment during her Australian Open clash with Caroline Wozniacki AFP / John DONEGAN

Bajin, who used to coach two-time Grand Slam winner Naomi Osaka, fired back.

"Just to shut some people up and end this useless convo," he wrote on Twitter.

"Dayana was really struggling since days with her leg, but since y'all are all doctors and coaches you know better then she herself or our whole team who's working with her. #focusOnYourself "

Reaction on social media overwhelmingly backed Wozniacki, with users noting Yastremska, who won two singles titles last year, had used the timeout tactic before at crucial moments.

"Mate, I'm a big fan... but really? Come on you need to clean that out of her game," said one person replying to Bajin, in sentiments echoed by others.

Wozniacki, in her final tournament before retiring, plays Tunisia's Ons Jabeur in the third round on Friday.

Tunisia Twitter