Théo Pourchaire back for Toronto after Alexander Rossi injured

Théo Pourchaire is returning to Arrow McLaren for Sunday's IndyCar race in Toronto after Alexander Rossi broke his right thumb in practice Friday.

Pourchaire rejoins Arrow after he was surprisingly dropped by the team in June so it could sign 19-year-old Nolan Siegel to a multiyear contract.

In announcing the quick substitution, Arrow McLaren said Pouchaire was flying to Toronto from Europe and would miss Saturday morning's practice session. He arrived in time to qualify the No. 7 car Saturday afternoon.

Rossi was injured when he crashed into the Turn 8 wall trying to save the car.

"It's unfortunate because the injury occurred when I almost made it around the corner and I didn't want to give up on it, so I didn't quite get my hands off the wheel in time," Rossi said in a statement.

Rossi said he hopes to recover in time for IndyCar's next race at Gateway on Aug. 17 after a break for the Olympics. He returned to Indianapolis to begin rehab on the thumb.

Pourchaire competed in five races for Arrow McLaren earlier this season after helping to take over the No. 6 car for the injured David Malukas . Pouchaire's best result was 10th at the Grand Prix of Detroit.

The move had stunned Pourchaire, who tried to find another seat in IndyCar but finally returned to France this week before his abrupt return to North America.

Rossi, meanwhile, was told in June that he and McLaren were parting ways at the end of the season.

The Associated Press contributed to this report.