Allmendinger started off his professional motorsports career in open wheel racing, winning the 2003 Atlantic Championship and then moving to the Champ Car World Series in 2004 with RuSport. His best season was in 2006 when a move to Forsythe rewarded him with five wins and third place in the championship.
After that, Allmendinger moved to NASCAR - initially with Red Bull. He ran a total of 173 race over the course of six years, during which time he clinched two pole positions and claimed his best race result last year with Penske at Martinsville in April, when he finished just behind race winner Kasey Kahne in second place.
Allmendinger also co-drove the #60 Michael Shank Racing Ford Riley to victory in the 2011 Daytona 24 Hours, and duly re-teamed with Justin Wilson, Oswaldo Negri Jr, John Pew and new addition Marcos Ambrose to take the car to third place in this year's event - despite having to come back from eight laps down with early technical trouble.
However, even though Allmendinger stayed close with Penske, his prospects for an immediate return to either NASCAR or IndyCar with his old boss looked slim. In his absence, Penske had gone on to win the 2012 Cup championship with Brad Keselowski and then confirmed Joey Logano as the long-term replacement in Allmendinger's former race seat in the #22.
Over in IndyCar, it looked as though Penske was downsizing from three to two full-time cars after letting Ryan Briscoe go while holding on to Will Power and Helio Castroneves.
But if the Sebring test goes well, it's expected that Allmendinger will make his IndyCar début with Penske in the second race of the year at Barber Motorsports Park in Alabama on April 7. It's understood that the team would also like to enter him in the Long Beach race a fortnight later, as preparation for the Indy 500 itself.
“Just getting back in a Roger Penske car after everything that happened means the world to me," he said. "That he put his faith back in me is amazing ... I can't begin to explain what it means that he believes in me enough to give me another chance."
The news got the thumbs up from Michael Shank, who himself still seeks to set up an IndyCar team in the future in partnership with Allmendinger.
“There will be a lot of pressure on [AJ], but if he manages it well and keeps expectations in check and focus on every task, he'll be fine," said Shank, who added that his respect for Penske had shot up with today's news. "It takes a lot to re-hire somebody after you've fired them, in any business."
But Allmendinger knows that he needs to put aide the circumstances that led to the moment, and just seize the opportunity in front of him with both hands without any distractions.
"There's no pressure with this test, but I'll put the pressure on myself," he added.