Lyon's new mystery ball unveiled?

Is Nathan Lyon's new mystery ball no longer a mystery?

Amid Pakistan's batsmen taking to Australia's bowlers in Dubai on Saturday, Lyon provided a talking point with a delivery that had no place amongst his normal repertoire of traditional off-spin deliveries.

Lyon, who finished with 2-220 from 53 overs for the match, gave what could be the first public viewing of his new delivery which he has been working on for some time.

The Australian spinner’s first mystery ball, light-heartedly nicknamed Jeff, has rarely been seen since he used it to dismiss South Africa's Jacques Rudolph in Brisbane in 2012.

Instead, Lyon has relied on the classical off-spinner's method of flight, bounce and regulation spin to pick up his 114 Test wickets.

In May, he revealed he was working on "Jeff's twin brother", but declined to reveal too much more about the new variation before working on it with spin bowling legend Muttiah Muralidaran on a trip to Sri Lanka in June.

He later explained the delivery was a form of "back-spinner" and during Australia's tour match against Pakistan A last week, he hinted that a reveal was imminent and also suggested there would be more new deliveries to come.

"That's another surprise you will just have to wait and see next week," he said.

"We have been working with few different things so it's not just a couple of balls, there is more than two.

"Both SOK (Stephen O'Keefe) and I have been working with Murali on few different things and few tricks.

"We have to just put them out there in the play and see how we go."

Bowling to Pakistan wicketkeeper-batsman Sarfraz Ahmed in the final session on Saturday, Lyon bowled a ball that grabbed the attention of commentator and former Test batsman Dean Jones.

But was it the long-awaited arrival of Jeff's twin, or is it another variation?