Theo Pourchaire replaces the injured Alexander Rossi for Arrow McLaren's IndyCar team in Toronto

TORONTO — A broken right thumb forced Arrow McLaren driver Alexander Rossi out of the IndyCar street race at Exhibition Place, giving Frenchman Theo Pourchaire his sixth start of the season.

Rossi was injured in practice Friday when his car hit a tire barrier and then skidded into a concrete wall. The 2016 Indianapolis 500 winner already returned to Indianapolis, where he will begin rehabbing the thumb.

It's unclear how long Rossi will be out, but after the race Sunday, the series will take a three-week break. IndyCar's next race is scheduled for Aug. 17 near St. Louis.

Pourchaire arrived at Toronto’s Pearson Airport less than two hours before the qualifying, then ran a lap of 1:01.6071 in the No. 7 Chevrolet. He will start 26th.

Pourchaire is the reigning F2 champion and had planned on racing in Europe this year. But his focus turned to IndyCar when McLaren brought him in as the injury replacement for David Malukas and then named him the full-time driver when the team fired Malukas for missing too many races with a broken wrist.

Then, Pourchaire ran only five races for McLaren before the team abruptly released him when 19-year-old Nolan Siegel became available.

The move stunned Pourchaire, who tried to find another seat in IndyCar but finally returned to France this week. Rossi, meanwhile, had been told in June that he and McLaren were parting ways at the end of the season.