Michael Nolan, the 23-year-old former Oakland Athletics prospect who was shot on Sept. 18, has died, according to multiple reports.

Nolan underwent surgery Tuesday to relieve pressure on his brain, his mother told News 12 Hudson Valley, and was declared brain dead Thursday afternoon at Jacobi Medical Center in the Bronx, where he had been since being placed in a medically induced coma following the shooting.

The Journal News reported on Friday afternoon that Nolan had been declared dead, a day after conflicting reports were published about the former prospect's status. The newspaper reported a day earlier that Nolan "has not been pronounced dead as of mid-afternoon Thursday," after Nolan's former high school coach tweeted that the lefty had died. The A's also released a statement on Nolan's passing on Thursday, but his death was confirmed by family members on Friday afternoon.

"This is just heartbreaking. Just totally heartbreaking," his mother, Donna Nolan, told The Journal News. "For no reason whatsoever this happened to my son and it's just heartbreaking."

Athletics general manager David Forst released a statement of support to the family on Thursday.

"On behalf of the entire A's organization, I send my deepest condolences to Donna and Jimmy Nolan," Forst said. "Michael will always be a member of the A's family, and our thoughts and prayers are with his family and friends for their tragic loss."

The police told media that the shooting, which took place shortly after midnight on Sept. 18, may have stemmed from an argument about a drag race two days prior. Nolan was hit in the head and shoulder while standing in a Burger King parking lot with friends. The shots were fired from a car, police believe, and it is not clear whether or not Nolan was the intended target.

"It's very overwhelming right now," Donna Nolan said told The Journal News. The family indicated they would donate their son's organs.

"There are no arrests at this time and the investigation is continuing," Yonkers police department spokesman Lt. Patrick McCormack said on Thursday.

Yonkers Police Commissioner Charles Gardner asked the public for help in solving the crime on Friday.

"We have a full-court press trying to find the individuals responsible for this senseless act of violence here in our city," he said.

A 6-foot-7 left-hander, Nolan was selected out of Oklahoma City University 552nd overall in the 2014 Draft. He went 6-3 with a 3.32 ERA while striking out 84 batters over 76 innings in 2014, his junior season with the Stars. He overcame Tommy John surgery before being drafted by Oakland.

Nolan was placed on the restricted list on July 14, 2014, and never pitched in an official Minor League game.