Tim Paine delivered a damning assessment of Australia's batting frailties and said they "weren't up for it" after Pakistan wrapped up the series with a crushing victory in Abu Dhabi.

Mohammad Abbas claimed his first 10-wicket Test haul by taking 5-62 in the second innings as he combined with Yasir Shah (3-45) to torment the tourists, who managed 164 on day four to suffer a 373-run loss and a 1-0 series defeat.

Usman Khawaja came to the rescue with a brilliant century when Australia defied the odds to salvage an unlikely draw in the first Test in Dubai last week, but the opener was unable to bat on Friday due to a knee injury which could require surgery.

Paine, who made only three runs in his two knocks in the second Test, pulled no punches with his verdict on his side's shortcomings after a defeat which leaves them in fifth spot in the rankings.

"It's bitterly disappointing, no doubt. We had some momentum from the first Test, started really well here and then from 57-5 [in Pakistan’s first innings] it went a bit pear-shaped to be honest all over the field," said the Australia captain.

"It's hard to swallow. We weren't up to it. To come out and do that this Test is like taking one step forward and two steps back. It's really frustrating.

"There's no doubt this [the battling collapses] has been happening for too long for the Australian cricket team, not just our Test team but probably domestically there's a lot of collapses throughout our batting group and I think a lot of it can be technical.

"Some guys will be mental and other guys will be tactical, or your plans not being right for certain bowlers. There's no shying away from the fact we have a hell of a lot to do on our batting, in this team and through the whole country.

"Clearly it would be a pretty exciting time to be a batsman around Shield cricket at the moment if you're scoring 100s, there’s no doubt about that. There's opportunity for everyone and the batting group that are here are also a part of that."