Fernando Alonso: Indy 500 final laps will 'shock', says Franchitti

Alonso tested his McLaren-Andretti Dallara-Honda for the first time at Indianapolis earlier this week ahead of his shock appearance in the 500 in place of the Monaco Grand Prix.

While team owner Michael Andretti said Alonso was already showing signs he "gets" oval racing, four-time IndyCar champion Dario Franchitti said his inexperience would most likely reveal itself late in the main event.

"It'll be difficult, no one's under any misapprehension here," said Franchitti at a McLaren event promoting Alonso's appearance with IndyCar CEO Mark Miles, Max Chilton and Zak Brown.

"Talent-wise, can he do it? Absolutely. But again, inexperience - that will be the tough thing.

"If it comes down to a caution with 20, 25 laps to go, and everyone pits for new tyres, that's when all bets are off.

"At the start of the race, people are a little nicer to each other, and if you've got half a pass made, they'll let you through.

"As business picks up toward the end, that goes away in a hurry.

"So I think that will come as a shock."

Alonso is part of six-car Andretti entry for Indy, joining regular drivers Takuma Sato, Marco Andretti, Ryan Hunter-Reay and Alexander Rossi and fellow debutant Jack Harvey.

Franchitti said the difference between drivers with and without experience was knowing what counts the most at different points of the event - and that Alonso would also have to contend with a higher-than-usual number of potential winners.

"I think [Alonso] will learn that throughout the week, he's going to build up all that information," he said.

"But it will be very, very difficult to compete with Scott Dixon, Tony Kanaan, [two-time winner Juan-Pablo] Montoya.

"Montoya is really hungry to win. He's in an Indy-only deal with Penske this year. And [Helio] Castroneves always seems to get it done.

"Also - and I think this is something that will be different for Alonso - 20 or so drivers can realistically be competitive enough to win that race just on pace, never mind strategy.

"He's going to have to work very hard with his engineer to get the absolute maximum out of that car before the race starts.

"Whereas a lot of the time in F1 you've got what you've got because of the latest developments.

"This is about just constantly polishing on it to make sure you've got the best car for the end."