Brad Haddin put the interests of his team before himself by wicketkeeping for more than two hours with a shoulder injury which has cast doubt over his availability for the start of the Australian summer.

The veteran wicketkeeper is refusing to have scans for now as "scans only rule you out, not in" and was in considerable discomfort on Friday night.

Australia's medical staff are confident Haddin can bat though but the vice-captain was unsure if he would be able to don the keeping gloves in Pakistan's second innings.

"I don't know, I would only be speculating. It's pretty fresh now, so time will tell," Haddin said.

"I think I'll be fine to bat, I don't think there'll be a drama. It'll be uncomfortable but I think I'll be fine."

Haddin suffered the injury in the sixth over of play on Friday after landing heavily on his right shoulder taking a delivery from Peter Siddle.

He remained on the field for another 15 balls before leaving for treatment, handing the gloves to David Warner, but surprisingly returned for the second session.

It was not until the new ball was taken shortly after tea that Haddin went off again.

"We believe Brad has injured his AC joint after falling on it. He will have treatment overnight and we are confident he will be able to bat," said Cricket Australia doctor Peter Brukner.

Former Test batsman Dean Jones, who is commentating on the game, said: "Just spoke to Brad Haddin.. Shoulder is swollen and angry.. He thought it did dislocate & it Popped back in.. He will be sore tomorrow!"

The full extent of Haddin's injury will not be known until he has scans but the wicketkeeper is refusing to go down that path, presumably for fear of what they may reveal.

"It's uncomfortable but it's only fresh now. I'll know more tomorrow," Haddin said.

"I can't really give much now. There's no way I'm going for a scan, it only rules you out."

A serious injury to Haddin would be a blow for Australia, which hosts South Africa in a five-game one-day international series followed a four-Test series against India starting on December 4.

Haddin said he wanted to return to ease the pressure off Warner so that the opener could stay as fresh as possible before opening the batting.

"It was my decision to go back out. I had to also think of Davey opening the batting, I didn't want him to have to keep the whole time and then have to come in to bat," Haddin said.

"I wanted to see how I'd go and basically make sure he had the best preparation he could to open the batting. That was a big part of the reason why I went back out. I didn't want him to have to do it and then come in and bat a day and a half."

Such was the discomfort Haddin was in he was unable to move his right arm while walking and was in pain on the odd occasion he instinctively shot his right arm up to appeal.

"It was like mice getting tested wasn't it, with the buzzer," Haddin said. "Yeah, it hurt."

He left when the second new ball was taken as he did not feel he could raise his arms quickly enough to handle the extra bounce.

Haddin said he was proud of Australia's attitude in the field as Pakistan amassed a massive 6-570 before declaring in the final session. Australia resume on Saturday 1-22, trailing by 548.

"No one threw in the towel. It was a pretty uncompromising wicket and we knew it was going to be that way for whoever lost the toss," Haddin said.

"Our guys kept fighting.

"Pakistan batted very well and they deserve a lot of credit. They were hungry for runs and hungry to bat a long period of time.

"It's our turn now. We've got to make sure we apply ourselves and get stuck in.

"It's real Test match cricket where you have to work, and it's hard work.

"It's up to the batters now all of us to dig in and see how deep we can get this game."