Day, 27, of Freeport, N.Y., struggled to find his footing against Conwell in the fight at Wintrust Arena in Chicago on Saturday night. Conwell, a 2016 U.S. Olympian, dropped Day twice in the fourth and eighth rounds before landing a left hook early in the 10th that instantly knocked him out cold.
The New York fighter was treated by a doctor in the ring for several minutes. It was unclear whether he regained consciousness. He was then taken off on a stretcher by paramedics and rushed to the hospital.
Day suffered a seizure while on the way to Northwestern Memorial Hospital, sources with knowledge of his condition told ESPN. He was given a breathing tube in the emergency room and at some point went into a coma, a source said.
It was unclear whether Day was placed into a medically induced coma to allow time for the brain to reduce swelling, according to ESPN.
There has been no official update on Day’s condition.
Eddie Hearn, the managing director of the promoter, Matchroom Sport, said only he “didn’t think the situation is great.” He said he felt Day’s family and manager, Lou DiBella, would want to make their own statement.
Following the scare in the ring, DiBella asked for prayers on Twitter.
“Please pray for Patrick Day,” he wrote. “Please. Such a good person.”
Conwell also asked the public to keep Day in their prayers. In a message on Twitter, Conwell wrote: “Praying for you,” and “Keep fighting!”
Day (17-4-1, 6 KOs) suffered his second loss in a row at the hands of Conwell, who improved to 11-0, with eight KOs.
Day has won several accolades in his career. In 2012, he was the New York Daily News Golden Glove Champion, USA Boxing welterweight national champion, and winner of the Sugar Ray Robinson Outstanding Athlete award, according to ESPN.
The bout was on the undercard of Oleksandr Usyk’s heavyweight debut against Chazz Witherspoon. Usyk won with a seventh-round knockout.
The Associated Press contributed to this report.