Andrew McGlashan is a deputy editor at ESPNcricinfo
Pat Cummins is confident Australia's fringe spinners will be ready to face Pakistan if called upon despite limited - and in Ashton Agar's case no - first-class cricket this season.
Swepson, who has been with the various Test squads almost throughout Covid-19 bubble life, would be the favourite to come into the side and has at least had three first-class matches either side of the Ashes albeit in one of those against New South Wales he bowled just two overs.
Last week he got through 52 overs against Victoria for a single wicket but last season's return of 32 wickets at 23.40 for Queensland suggests he is ready for the step up.
Agar, meanwhile, has not bowled in a first-class game since the end of last season having been part of Australia's T20I set-up. He played the last of his four Tests in 2017 and in the 2020-21 Sheffield Shield season took 14 wickets at 42.21 in four matches.
"Swepo has spent a lot of time around the Test side, so even though he might not have played a lot of red-ball cricket he's been bowling lots and lots in the nets and the same for Ash," Cummins said. "He's been playing quite a lot of international cricket the last couple of years so while it's a different format, different feel, really confident in their form that either of those would be able to slot straight in."
It would likely require Australia to significantly alter the balance of their side for Agar to earn a spot unless injury or Covid struck. Marnus Labuschagne, who took seven of his 12 Test wickets during his maiden series against Pakistan in 2018-19, provides another spin option.
Even if Australia stick with Lyon as a single specialist spinner - which would appear possible for the opening Test in Rawalpindi where quicks have averaged 27.63 in the three most recent Tests - there will still be at least one pace bowler unfortunate to miss out.
"In terms of the fast bowlers, Scotty Boland has just had a fantastic summer, Josh Hazlewood and Starc are superstars so already one of those is going to miss you would expect," Cummins said. "Everyone realizes there will be some tough calls, not much you can do about it. The reality of having a really, really strong squad is a couple of people are going to miss out of every Test."