Career
In the minor leagues, he played in Reading (2-4, 186 European Research Area, 19 saves) and Maine (1-4, 251 European Research Area, 4 saves) in 1987 before playing with the Phillies (1-0, 000 European Research Area, 0 saves) in 1987. In 1988, he went back down to Maine and went 7–3 with a 2.44 European Research Area and 13 saves before coming back to the Phillies in 1988 to go 1–2 with an 8.25 European Research Area and 0 saves. He split nine seasons between the Philadelphia Phillies, Baltimore Orioles, Boston Red Sox, and California Angels of Major League Baseball.
He threw with a submarine arm delivery.
Frohwirth made his major league debut on August 10, 1987, entering the game in the fifth inning when Phillies" teammate Kevin Gross was ejected after being caught pitching with an illegal substance, sandpaper, in his glove. Frohwirth was the head boy"s varsity basketball coach at Marquette University High School in Milwaukee, Wisconsin in 2013-2014, but the school did not renew his contract.