When Garrett Marchbanks’ motorcycle went end over end on the muddy track at Rice-Eccles Stadium last week, so did his shot at the AMA Supercross 250SX East series podium.

The Coalville rider suffered a bruised lung and other internal injuries during a crash on the opening laps of the 250SX East main event on June 7. Representatives from his Monster Energy Pro Circuit Kawasaki team said Marchbanks is not expected to finish out the final two races of the season. The first of those races was Wednesday and the last is the East/West championship on Sunday.

Marchbanks, 18, had been rapidly climbing up the standings since making history in Daytona, Fla., on March 7, when he became the first Utah athlete to win a race in the 45-year history of Supercross. That win propelled him into third place in the overall standings just as COVID-19 caused racing action to grind to a halt.

Racing resumed two months later with a five-event slate at the University of Utah stadium, where Marchbanks had been attending races since he was a toddler. While Chase Sexton and Shane McElrath battled for the championship, Marchbanks quickly entrenched himself in his top-three position. He placed third in the May 31 opener, marking his third career podium and took fifth on June 3.

Marchbanks got off to a rough start out of the gate on a muddy track in the June 7 main event and his lime green bike went spiraling down the track within the first two laps. He was able to sit up trackside but was carried off on a stretcher and taken to the nearest hospital.

At the time, Marchbanks was optimistic he would be able to return to defend his position, especially with East racers scheduled to have a 10-days break before their next event.

“Today was a rough day. Between the rainy weather and sloppy track conditions, I didn’t help myself with the bad start in the main event,” Marchbanks said in a statement released by his team. “My ribs and back are really sore from my crash so I will get checked out, take these 10-days to recover and go from there. I hope to be back out there a week from Wednesday and make up some points.”

Marchbanks was still in third with 119 points entering Wednesday’s race and held that position despite not competing. He could feasibly finish out the season in the top three, but several riders, most notably Enzo Lopes (fourth, 111 points) of North Carolina, Jo Shimoda (fifth, 109) of California and Jeremy Martin (sixth, 105) of Minnesota are within striking distance.

Rookie Pierce Brown, 18, of Sandy, began Wednesday’s races ranked ninth. He moved up a spot to eighth, however, by posting his second straight fourth-place finish, his best showing as a pro.

Sunday’s championship is scheduled to start at 1 p.m. on NBCSN. Starting at 2:30 p.m., action will be aired on NBC.