Australia’s injury ravaged Test fast bowling stocks have dwindled further with veteran seamer Peter Siddle ruled out of the second Test against New Zealand starting on Saturday due to an ongoing back complaint.

Siddle, who returned to the Test line-up for last week’s opening match of the series in Wellington having missed the final Test of the Australian summer with an ankle problem, suffered back spasms on the penultimate day at The Basin Reserve.

"Peter experienced some discomfort in his back during the first Test in Wellington and has not recovered sufficiently enough to play the Test,” Cricket Australia’s Bupa Support Team Physiotherapist David Beakley said today.

"At this stage the plan is for him to stay with the squad in Christchurch for the remainder of the tour before returning to Melbourne for further investigation.”

Siddle did not bowl as Australia completed a thumping victory by an innings and 52 runs at Wellington last Monday, and his place in the XI likely to be filled by fellow Victorian James Pattinson.

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However Pattinson is also on the recovery trail having missed almost six weeks of cricket due to shin soreness and was overlooked for the Wellington Test amid concerns he would not be able to withstand a five-day bowling workload.

If he is once again deemed too much of a risk for a Test match that Australia must at least draw in order to secure the world’s number one Test ranking and accompanying prize money, then uncapped South Australia seamer Chadd Sayers will be called up for a Test debut.

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Asked in the wake of last Monday’s Test win whether he felt Pattinson would be available for this week’s re-match in Christchurch, Australia captain Steve Smith gave every indication the injury plagued fast bowler was close to gaining the all-clear.

Provided he gets through the major pre-Test training session in Christchurch this afternoon.

"He's done quite a lot of bowling this week,” Smith said on Monday afternoon.

"He's had quite a few sessions and I saw him bowl this morning actually and it looked like they were coming out pretty nicely, and quite fast.

"So I think he's tracking pretty well to be fit for the next Test match.”

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While Pattinson would regularly bowl around 15km/h faster than Sayers, he can also be expensive if his rhythm is found wanting as shown in his first Test appearance in almost two years against the West Indies in Hobart last December when he returned 0-68 from 10 overs in the first innings.

However, the highly rated speedster found his range in the second innings and snared 5-27.

The loss of Siddle, who regularly fills the dual role of wicket-taker and runs-stopper which allows Smith to rotate his more mercurial strike bowlers from the other end, leaves the selectors with something of a dilemma heading into such a vital match.

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In Pattinson, they have a bowler who has shown he can perform at Test level and be a match winner when fit and firing but who can also bleed runs which might play into the hands of NZ’s destructive top-order that includes big-hitting Martin Guptill, Kane Williamson and Brendon McCullum.

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But while Sayers is renowned for his capacity to run in all day and unerringly hit a nagging line and length, his ability to adapt to Test cricket is untried and the fact that medium-fast bowlers can become fodder in international cricket might also prove costly.

If Pattinson is unable to dispel fears that he might break down in the course of the Test and leave Smith a bowler shy, then that decision becomes academic.