Gabrielle Schoeneweis, 39, was found in her bedroom by the couple's 14-year-old daughter around noon, according to the Arizona Republic. She was unresponsive when Maricopa County sheriff's deputies arrived at 12:11 p.m.
The cause of death has yet to be determined, but a spokesperson for the Maricopa County Sheriff's Office said there were no signs of foul play.
The couple had four children. Schoeneweis, 35, a lefty relief pitcher for the Diamondbacks, has pitched for six teams in his 10-year big league career, including the Anaheim Angels, Chicago White Sox, Toronto Blue Jays, Cincinnati Reds and New York Mets.
On Wednesday, Diamondbacks manager A.J. Hinch said he heard the news an hour before the first game of the team's doubleheader against the Florida Marlins in Miami. Hinch then called a team meeting.
Diamondbacks General Manager Josh Byrnes said the team arranged a cab to the airport and a flight to Phoenix for Schoeneweis, offering to send Schoeneweis' pal Jon Garland with him on the flight. Byrnes said Schoeneweis preferred to go alone.
"We're trying to support Scott as best we can," Byrnes said. "It seems like everyone was taking it pretty hard."