In August, Pakistan topped the ICC Test rankings for the first time.

Its ascension to No.1 followed a run of six consecutive Test series without defeat, among them impressive victories over Australia and England (both at their adopted ‘home’ in the United Arab Emirates) and draws against New Zealand and England (away).

They have since slipped to fourth place, largely due to the vagaries of the system and a 2-0 series loss in New Zealand in November, but the side led by former Australia coach Mickey Arthur will be quietly confident against the rejuvenated – if unsettled – hosts this summer.

Left-arm paceman Mohammad Amir looms as Pakistan’s trump card and will be licking his lips over the prospect of bowling under lights with a pink ball at the Gabba in Brisbane this week.

His ability to swing the ball, prodigiously and at serious pace, was on display in a tour match against a Cricket Australia XI in Cairns last week, where he took five wickets.

But it is the 24-year-old’s backstory, involving time behind bars and a five-year ban from the sport, that makes him the most fascinating character of the three-Test series.

At just 17, he made his Test debut in Sri Lanka – and took six wickets. By 18, he already had 50 scalps in the longest form of the game.

That Amir was a star on the rise was crystal clear.

Amir’s world was about to turn on its head, though, when he was accused of bowling deliberate – and pre-planned – no-balls during a Test at Lord’s in 2010 for betting markets, charges to which he eventually pleaded guilty.

Amir’s captain Salman Butt and paceman Mohammad Asif were also involved, but while those two were given life bans in addition to their prison sentences, the teenage talent was not, due to his age and immaturity.

A fresh-faced Amir celebrates a wicket before his ban. Photo: Getty

Amir still served time behind bars (three months that ended in February 2012) and was banned from cricket for five years. But he frequently apologised and worked his way back into Pakistan’s team once his suspension ended.

Initially, some of his teammates were reticent to play alongside him, but he fought on and eventually made his Test return at, of all places, Lord’s.

“Life was very tough and there were times I thought I might not be able to play again,” he told Sky Sports in July.

“I didn’t pick up a ball for three years … it was very depressing … the main aim for me [now] is to be the world’s best bowler.”

It is an aim that is certainly realistic.

He has quickly slotted back into Test cricket, taking 25 wickets in eight matches, and further improvement looks likely, with ex-Australian quick Mitchell Johnson tipping he will wreak havoc at the Gabba.

“When we got to England [in 2010], he was unplayable when it was seaming,” Johnson told The Australian this week.

“I think it’s going to be the same story under lights at the Gabba, especially if they leave some grass on the wicket.”

It is a view shared by Michael Hussey, who told the Cricket Australia website: “He’s an outstanding talent. I feel like he’s done his time and he’s a class bowler … he bowls extremely well with the new ball but is also very good with the old ball as well.”

Pakistan’s other key men

Misbah-ul-Haq
The 42-year-old skipper (yes, that’s right) averages 47.79 with the bat and made two centuries in the same Test against Australia in 2014. Has only played two Tests in Australia, though, and can be susceptible to fast bowling.

Misbah is the oldest man still playing Test cricket. Photo: Getty

Younis Khan
The other veteran in Pakistan’s batting order, the 39-year-old has an outstanding batting average of 52.89 from his 112 Test matches. It’s even better against Australia, at 56.66. The key wicket.

Wahab Riaz
Capable of bowling over 150 kilometres per hour, left-armer Riaz is extremely sharp – if a little inconsistent. His fierce spell against Australia in last year’s World Cup quarter-final was epic. Test bowling average of 33.61 a little unflattering.

Yasir Shah
Did not make his Test debut until he was 28 but the leg-spinner, likened to Shane Warne, already has 116 wickets in just 20 Test matches. Took 12 against Australia in two Tests in 2014. Can really turn a ball.