Michael Caruso is making an unexpected return to Garry Rogers Motorsport for the Watpac Townsville 400, six-and-a-half years after leaving.
Caruso, a full-time GRM driver for five seasons from 2008, is standing in for the injured Richie Stanaway at Boost Mobile Racing.
He replaces Stanaway's PIRTEK Enduro Cup co-driver Chris Pither in the #33 Commodore, Pither having contested the Sunday Winton race and Hidden Valley event.
While it is an unusual situation, especially given the complexities of neck injuries such as Stanaway's, substitute drivers are more common than you might think.
You only have to go back to the 2017 PIRTEK Enduro Cup to find the most-recent stand-in, Andre Heimgartner at Brad Jones Racing.
Heimgartner jumped in alongside Tim Slade on Friday at Bathurst when Ash Walsh withdrew following a sportscar accident, then grabbed a podium on the Gold Coast.
If you go back to 1999, only four seasons have passed without some sort of substitute arrangement, overlooking permanent driver changes.
Supercars.com takes a look back through some of the more memorable and significant supersubs.
Steven Johnson for Dick Johnson – 1999 Calder Park
Supercars fans got an early taste of life without Dick Johnson on the grid during his 1999 farewell tour.
The five-time champion battled sinus problems towards the end of his career, and missed the Calder Park round.
Fortunately, there was a readymade solution that wouldn't trouble the DJR sticker department – Steven Johnson.
Before teaming up with his father in the enduros, and replacing him in 2000, Johnson junior slotted into the #17 Shell Falcon in Melbourne.
He finished 10th, sixth and fifth in a promising weekend.
Cameron McConville for Craig Lowndes – 1999 Symmons Plains
That 1999 Calder Park event is best-known for Craig Lowndes' mammoth rollover at the start of Race 2.
A violent accident left the Holden Racing Team star with damaged ligaments in his left knee and requiring surgery.
Lowndes was, as you might expect, ruled out of the Symmons Plains event a fortnight later.
His HRT enduro partner Cameron McConville got the call-up, fresh from a three-event privateer run in a John Faulkner Racing VS Commodore that included Calder.
McConville was in HRT's older-model VS Commodore spare, and qualified eighth then finished Races 1 and 2 sixth and seventh.
However an overheated engine, the result of a blocked radiator in the wet conditions, meant he did not start the final.
Lowndes returned at Winton and went on to seal the title with enduro podiums alongside McConville.
Simon Wills for Wayne Gardner – 2002 Queensland 500
Not all substitute appearances are down to injury or illness.
Wayne Gardner juggled Supercars enduro roles in the early 2000s with a full-time gig in what's now known as SuperGT in Japan.
That included Queensland 500 date clashes in 2000 and '02, years he was signed by Glenn Seton and then Stone Brothers Racing for Bathurst.
In 2002, Simon Wills was drafted in by SBR to partner David Besnard for the opening enduro, and the pair took a memorable victory.
Gardner then crashed the Caltex Falcon in practice at Bathurst, ruling it out for the weekend in what was the 500cc motorcycle champ's last act in a Supercar.
Besnard, though, eventually drove alongside Seton after the latter's co-driver Owen Kelly was struck down by a dodgy prawn cocktail.
This era also featured a handful of full-timers from smaller teams jumping ship to bigger operations for the enduros.
Paul Weel was a famous example in 2002, partnering Marcos Ambrose at SBR and leaving co-driver Geoff Full to lead PWR Racing.
John McIntyre for David Besnard – 2004 Gold Coast
Besnard is central to another instance of a healthy driver needing a replacement.
By now with WPS Racing, Besnard was parachuted out of his regular Falcon Supercar and into a WPS-backed Champ Car for the Gold Coast Indy.
In a one-off appearance with Walker Racing, Besnard stayed out of trouble and finished a credible seventh.
It gave John McIntyre what was ultimately his only single-driver Supercars outing.
An NZ Touring Car mainstay, and three-time champion, McIntyre had made his debut in that year's enduros.
McIntyre made 22 Supercars starts between 2004 and '13 but finishes of 19th and 18th on the Gold Coast – then a sprint round – were his only outside the enduros.
Tony Longhurst for Mark Skaife – 2007 Sandown 500
The Holden Racing Team's preparations for the 2007 Sandown 500 were thrown into disarray when Mark Skaife suffered appendicitis in race week.
Having fallen ill on the Wednesday evening, he had the appendix removed on Thursday and despite visiting the circuit on Friday did not get behind the wheel.
HRT flew Tony Longhurst down from the Gold Coast, and moved full-timer Todd Kelly – scheduled to partner Skaife – back to his regular #22 with Nathan Pretty.
It meant Longhurst partnered Glenn Seton in Skaife's #2 Commodore, finishing 13th in what ended up being the two-time Bathurst winner's final Supercars race.
Andrew Jones for Jason Richards – 2010 Sandown and Homebush
The Supercars community was rocked in November 2010 by news Jason Richards had been diagnosed with cancer.
Richards was a much-loved member of the paddock, and lost his battle with adrenocortical carcinoma 13 months later, in December 2011.
His hospitalisation and diagnosis came in the week between the Symmons Plains and Sandown double-header, which followed the endurance races.
Andrew Jones, who finished third with Richards in September's Phillip Island 500, was summoned to return to BJR's BOC Commodore to finish the season.
BJR left Richards' name on the window for the remaining two events, with Jason Bargwanna then taking it over for the 2011 season.
Richards made an emotional, one-off return at the 2011 Australian Grand Prix event, recording a second-place finish in one of the non-points races.
Jacques Villeneuve for Greg Murphy – 2012 Townsville, Queensland Raceway and Sydney Motorsport Park
A back injury sustained during the Adelaide opener plagued Greg Murphy during his final full-time Supercars season.
The Kiwi legend missed five events in total from his 2012 Kelly Racing campaign.
Enduro driver David Russell made a pair of appearances in the Pepsi Max Commodore, before Jacques Villeneuve's high-profile recruitment.
The 1997 Formula 1 World Champion and '95 Indy 500 winner was thrown in the deep end in Townsville, without a pre-event test day.
He qualified 28th and last both days, failing to finish on Saturday then recording 24th on Sunday.
Villeneuve stayed on for the next two events, adding three more 24th-place finishes, with Murphy then returning for the enduros.
Scott McLaughlin for Alex Premat – 2012 Homebush
Scott McLaughlin's final day of the 2012 Supercars season at Homebush was a big one.
The young Kiwi sealed that year's Dunlop Super2 Series crown, still considered the strongest ever second-tier season, and made his solo main game debut.
McLaughlin's call-up came after Alex Premat was hit hard by a coolsuit failure and extreme heat, the exhausted Frenchman having to be pulled from the GRM Commodore.
Premat did not race on Sunday, with team boss Garry Rogers lining McLaughlin up after winning the Super2 crown.
While he had contested that year's enduros with Tekno, it marked McLaughlin's solo debut.
He finished 17th and graduated full-time to Supercars in 2013 with GRM.
Russell Ingall for James Courtney and Chaz Mostert – 2015 PIRTEK Enduro Cup
Russell Ingall was the common thread in a string of late-2015, injury-induced driver movements.
Ingall shifted to the Fox Sports broadcast team in 2015, after his final full-time season with Lucas Dumbrell Motorsport.
But he ended up driving a Holden Racing Team Commodore at Sandown and Bathurst, then a Prodrive Racing Australia Falcon on the Gold Coast.
The first followed a freak accident in pitlane at Sydney Motorsport Park in August, in which a helicopter demonstration scattered debris that struck James Courtney.
With rib and lung injuries sidelining Courtney, co-driver Jack Perkins stepped up to lead the #22 Commodore, and Ingall was signed to join him at Sandown and Bathurst.
Courtney returned on the Gold Coast, taking a victory with Perkins, while Ingall was by now in a Pepsi Max Falcon.
That was the first in a chain of moves following Chaz Mostert's season-ending crash in Bathurst qualifying.
Ingall teamed up with Cameron Waters on the Gold Coast, before Waters drove the Ford solo at Pukekohe and Phillip Island.
Waters' Super2 campaign meant he could not contest Homebush, with fellow PRA co-driver Steve Owen sliding in.
Paul Dumbrell for Nick Percat – 2015 Phillip Island
Nick Percat's 2015 season with Lucas Dumbrell Motorsport ended due to a blood infection caused by right-foot burns from an overheating exhaust header on the Gold Coast.
Percat contested the subsequent Pukekohe event but was then hospitalised in Melbourne, where the extent of the illness became apparent.
He contested the two Friday practice sessions at Phillip Island, and had been cleared to race, but opted against doing so.
Karl Reindler was originally on standby, but team owner Lucas Dumbrell took the opportunity to put brother Paul in the car for the weekend.
The elder Dumbrell finished all three races 21st before Jack Perkins took over for the Homebush finale.