News erupted late on Monday afternoon that Andretti Autosport had been shopping around the Indianapolis paddock looking for anyone willing to sell their starting place for next week's Indy 500, so that the team could insert one of their two regular drivers who failed to make it through Bump Day.

The top target for Andretti was the car of Bruno Junqueira, who qualified the #41 AJ Foyt car in 19th position on the first day of the weekend qualifying.

Less than 24 hours after the gunshot sounded out around the Indianapolis Motor Speedway to signal the end of qualifying and the sealing of the grid, the deal had been done and Ryan Hunter-Reay's team has managed to bump their driver back on the grid via the cheque book rather than the times sheets.

Any car that has a driver substitution after qualifying has to start from the back of the grid - but being at the back is still better than not being on it at all. While driver substitutions post-qualifying are relatively common for the Indy 500, it's believed to be the first time since 1981 that a driver has been substituted by a bumped driver from a rival team.

"I got bump," tweeted Bruno Junqueira at 10.30pm UK time on Monday evening. "I will not race in the #Indy500." In a more formal press release, he was quoted as saying: "I have to thank AJ, Larry and the team for giving me this opportunity to drive at Indy this year because otherwise I would have been riding my bike in Miami. I always respected A.J. before, but after working with him, I respect him even more.

"I had a great time working with him and Vitor, and I hope my work helped them this month. I also hope the team has a great race."

Asked later if he had received any promises of some future quid pro quo in return for dropping out, Junqueira said: "We'll see."

AJ Foyt had earlier said that he was funding Junqueira's Indy campaign "out of my own pocket" after failing to attract sponsorship, and it seems as though the canny four-time Indianapolis 500 champion has just converted that into a very successful financial investment. Even so, many were shocked that the motorsport legend who has always been such a stickler for the purity of the sport should be willing to agree to the move.

Talking about the Foyt/Andretti family relationship over the years, Foyt said: "We've been competitors for many years but still it's the kind of relationship when someone is really down and out, you can't turn your back on them--at least I can't.

"This is going back to the way racing used to be, where if people were in a lot of trouble, you tried to help each other out. I know it's a tough deal for Bruno but he understood the situation. I appreciate that more than anyone knows.

"Obviously, this is a unique circumstance for our team, but the thought of AJ Foyt joining forces with the Andrettis for the Indy 500 could result in something special," said Michael Andretti, seeking to put a positive spin on the move that it likely to be highly controversial if not outright mocked by fans and motorsports media. "It's a credit to AJ for being willing to help us with one of our full-season IndyCar entries at a time when we need it."

Read the full press release from AJ Foyt Racing announcing the driver substitution.

It isn't the first time that Junqueira has made it through Indy qualifying, only to have to make way for someone else. Two years ago while driving for Conquest Racing, he found himself switched out for none other than Alex Tagliani - the same driver who has claimed pole position this year.

"Junqueira plans to open 'Junky's Indy 500 Qualification Service' as part of Speedway Main St. renovation. Target market: rich kids," quipped freelance motor sports journalist Bill Zahren on Twitter when he returned home from Indianapolis to read the breaking news. "I'm only half joking that Bruno should go into business qualifying cars then taking the big cash to walk away."

The switch is not just a matter of vanity for Andretti Autosport, or trying to cover the embarrassment of not making the cut at the weekend; in many ways, having to buy their way back on to the grid is even more uncomfortable for the team than simply accepting the disappointment.

But the team have some major sponsors who are backing them in the clear expectation of getting their brands on TV for the Greatest Spectacle in Racing, and the consequences of not delivering that media coverage next Sunday were too dire for team owner Michael Andretti not to act - as Andretti acknowledged in the press release announcing the deal.

"I can't thank AJ and his team enough for giving us an opportunity to put Ryan, DHL, Sun Drop and our other valued sponsors in the Indy 500," he said

Assuming the paperwork goes through, Ryan Hunter-Reay - who ironically drove for Foyt's team in 2009 - will be the beneficiary. He was the driver bumped out in the last seconds when his team mate Marco Andretti managed to improve his time and bump the #28 off the grid, too late for Hunter-Reay to fight back.

Hunter-Reay had been distraught on Sunday evening. "I can't even process this right now. It's just devastating," he said. "This is terrible ... I don't know what to tell you. This is the worst. I don't think it's really hit just yet. I can't process it."

Now, he won't have to.

The deal appears to leave Mike Conway out in the cold, with the initial reports stating that Andretti Autosport was only seeking to buy up one place from other teams on the grid. Subsequent rumours suggested that the team were also desperately seeking to purchase a second grid slot for Conway as well, as he is ahead of Ryan Hunter-Reay in the IndyCar championship points after his race win at Long Beach in April, but this appeared to be merely rumour and speculation.

Among the candidates who could possibly be called upon to fall upon their sword and give up their race seat is Dale Coyne Racing's Alex Lloyd, whose stunning final attempt in the #26 was the spark that ignited the Bump Day drama by dumping out Marco Andretti to start with.

Meanwhile, the Andretti Autosport team have started to react to the seriously bad performance of the team as a whole over the Indy 500 practice and qualifying week. On Bump Day, Andretti had said that it had been "Probably my worst day as an owner," adding ruefully: "Had a few worse as a driver.

"I'm not very happy about [what happened]," Andretti had said earlier in the day. "I was given an indication it was going to be a lot different [from 2010 when Tony Kanaan was nearly bumped out of the race] and actually it was worse ... It's especially bad that we got out-qualified by a few cars that aren't as good as ours."

Team competition director Tom Anderson has been the first head to roll as he took the fall for Conway's #27 being dismal from the get-go. Anderson had been in charge of the team's competition department for the past two Indy 500 campaigns. He had been managing director of Ganassi Racing's CART operations in the 90s when they won four consecutive titles, and moved too become managing director of Fernandez Racing through the 2000s.

With all five of the drivers who failed to make the grid currently regular IndyCar season drivers with full-year deals and sponsorship arrangements, the news about Andretti's grid spot shopping has led to fevered speculation about a "domino effect" to other teams - such as Pippa Mann being ousted from her Conquest Racing #36 for the team's full-season driver Sebastian Saavedra, as happened with Junqueira/Tagliani two years ago.

Worryingly, Mann was tweeting that her mobile phone was dead - "Serious dead I-phone-itis!!!" - leading to immediate conspiracy theories that she was making sure no one could reach her with any bad news.

However, Conquest owner Eric Bachelart was quoted as saying on Monday that he had no plans to substitute out Mann: "I hope I never have to do that again," he said. "I really like her. She's done a great job, she's driven under control and been calm under pressure."

It's not clear just how happy the IndyCar sanctioning body will be if the qualification process of Pole Day and Bump Day is undermined by back room deals the day after the grid is meant to be finalised - or what powers they may have to deny driver swaps under the current regulations, if it came to that.

IndyCar may also have safety concerns if drivers who are judged to be too slow and too far off the pace, such as Conway, Saavedra and Dale Coyne's James Jakes, were to get grid spots without "proving" that they were up to the task.