Sprenger, who bombed in the final of his least favoured 200 breaststroke on Thursday night, qualifying 11th fastest and revealed that he had been suffering a shoulder injury for the past few months which physiotherapists believe could be a torn muscle.

But for Sprenger the more worrying aspect was that his stroke appeared to be misfiring. He laboured to the wall in one minute 02.30, behind England hope Adam Peaty (59.47) and 200 breaststroke champion Ross Murdoch (1:00.63). It was significantly slower than the 58.87 seconds the 28 year old posted at the national titles last April.

"The breaststroke, it's just gone ... it's just a mess at the moment," he said.

"The stroke it's just so foreign. I'm diving in and pulling out and there's just no drive, there's no power and there's no efficiency. It's just a challenge. I'm getting to the 50-metre mark and am already in pain and I don't understand. I really don't."

Sprenger looked shattered after the swim and his confidence has clearly taken a hit following his eighth placing in the 200 breaststroke final and Friday morning's heat. There was none of the bravado of the national titles in April when he confidently unveiled his 'golden cloak' and talked up his match up with Olympic champion Cameron van der Burgh.

"How do you go from a 58 seconds and four months later go 1:02 I can't even put a finger on it to be honest.

"Unfortunately there's no quick fix. I will just have to keep my head up for the rest of this meet and just try and do the best job that I can and hopefully there's still a place for me in the relay.

"The pain is one thing but when you dive in and you feel like your stroke is foreign you wonder how you did such things, how did I become world champion?

"Those things toy with your mind unfortunately and it's very hard to deal with but I've never really felt like this after being tapered and rested and ready to go. It just wasn't meant to be unfortunately."

Sprenger said team medics were looking into his shoulder injury that was causing significant pain.

"It's been going on for two or three months now and it just hasn't healed and they've been doing a lot of work on it," Sprenger said.

"It's just hurting so much in the water. I'm trying to block it out as much as I can but I just can't. It's just very strange.

"I don't know what to conclude but I think it's just unfortunately going to be one of those meets for me where i just have to push through and just work out some issues later I guess."

Meanwhile, three of Australia's world-record breaking 4x100 freestyle relay team, Cate Campbell, Bronte Campbell and Mel Schlanger, returned to the pool for the 50 free heats. Bronte Campbell produced another quality swim to break the Commonwealth Games record with a 24.52. But it lasted only until the end of the next heat when England's Francesca Halsall produced a 24.31.

"I held it for pretty much four records," said Bronte Campbell, who had only a few hours sleep because of the excitement of the previous night's performance.

"I'm pretty much happy with that. It's four minutes more than I was expecting."

Bronte Campbell also said she had been suffering from gastro in the leadup to the Games.

"I did come down with a sickness a few days ago, there has been a sickness going around the entire team,"  she said.

"I don't want to harp on about that. I'm not the only one who's been sick.

"I got sick in Glasgow, a few people got sick in Manchester but it's something that I'm over now. It didn't take much out of me. I got it really lightly."

Cate Campbell, who had also been ill in Manchester, is the second fastest for Friday night's semi-finals with a 24.33 and Schlanger was fifth in 24.87.

Cameron McEvoy started his Games campaign by qualifying fastest for Friday night's 200 freestyle final in 1:46.39 ahead of Thomas Fraser-Holmes (1:47.01) with 400 freestyle silver medallist David McKeon seventh fastest in 1:47.99.

Emily Seebohm and Belinda Hocking were the fastest qualifiers for the 100 semi-finals in 59.51 and 59.78 respectively while Madi Wilson was the ninth fastest in 1:01:05.

Fraser-Holmes also qualified fourth fastest for the 400 individual medley final in 4:15.34.

The men's 4x100 freestyle relay team, without its big guns of James Magnussen and Cameron McEvoy, was the fastest qualifier for Friday's final.

Para-swimmers Maddison Elliott and Lakeisha Patterson will also be competing in the 100 freestyle final (S8), with Elliott looking to break Jessica Long's world record of 1:05.63.

"I was talking at breakfast this morning saying I wanted to go for the world record and if I didn't get it I'd go for it tonight so I'm going to go out and go for it," Elliott said.