DES MOINES, Iowa (AP) — Two-time IndyCar champion Josef Newgarden was released from a Des Moines hospital on Monday and returned to his Tennessee home, where he will wait for an evaluation to determine if he can race this weekend at Indianapolis Motor Speedway.

Team Penske named Santino Ferrucci as its standby driver in case Newgarden is not medically cleared to compete on the road course at Indianapolis. Newgarden collapsed in the motorhome lot Sunday at Iowa Speedway following a late crash in a race he had dominated.

Although the American was cleared by the IndyCar medical staff after his crash, he later lost consciousness and fell to the ground in the bus lot, striking the back of his head. He was airlifted from the track in Newton to MercyOne Des Moines Medical Center to speed the 45-minute journey and avoid traffic from the postrace Blake Shelton concert.

Team Penske said Sunday night that all tests on Newgarden had been negative but he was hospitalized overnight for further evaluation.

Newgarden was already scheduled for a Thursday evaluation in Indianapolis to determine if he can compete Saturday. Per IndyCar regulations, a driver receives a secondary evaluation when a crash registers more than 80 G-forces.

There was no immediate word from IndyCar or Team Penske on the force of Newgarden's hit, but the scheduled second medical check would indicate his hit exceeded the threshold.

Newgarden, who won Saturday's race, dominated and led 148 of the 300 laps while trying to sweep the doubleheader weekend. But something on his Team Penske car broke with 64 laps remaining, and the 31-year-old from Tennessee spun hard into the outside wall — creating an opening for Pato O'Ward of Arrow McLaren SP to win the race.

Newgarden was visibly rattled after his mandatory check in the infield care center after the crash. He said the crash into the wall "definitely rocked me. I got a little bit shaken from it, but I'm OK.

"Definitely was a bit of a shot. I want to cry, so sad for my team. I don't know what happened," Newgarden said. "Everything felt fine to me. Totally unexpected and it caught me by my surprise. Team Penske is the best. I never have this stuff, so maybe we were due."

Chevrolet's initial diagnosis was that the suspension broke on Newgarden's car.

Newgarden was showing as the IndyCar points leader at the time of his crash; he's now tied for third in the standings with Scott Dixon.

Ferrucci was the replacement driver for Jack Harvey at Texas Motor Speedway earlier this year when Harvey suffered a concussion. He also ran the Indianapolis 500 and finished 10th.

Ferrucci is also scheduled to race the Xfinity Series event this shared weekend between NASCAR and IndyCar.

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