[5][6] (Reno was officially unaffiliated, but had agreements with the Twins and the San Diego Padres to take players on optional assignment from those teams.)

The Twins invited him to their spring training camp in 1976, where he successfully made the team, never having played Double or Triple-A baseball.

In 1976 he was the fourth-youngest baseball player in the AL.[1] His first major league home run was a game-winner off Catfish Hunter on April 18, 1976.

[11] Wynegar had six home runs and 47 RBIs at the midpoint of the 1977 season to make his second consecutive All-Star team.

He was traded along with Roger Erickson from the Twins to the Yankees for Larry Milbourne, John Pacella and Pete Filson on May 12, 1982.

[1] His average dipped to .267 in 1984, and fell further to .223 in 1985, in part due to an injury that occurred when he was hit in the head by a foul ball while standing in the on deck circle.

[17][23] In July 1986, Wynegar informed the Yankees that he had lost his enthusiasm for the game and did not want to play in New York anymore.

He called Clyde King, the general manager, and asked him for permission for some time off, explaining that he could no longer cope.

[22] But the game was no longer fun for Wynegar and he told King "this was no one-day thing," departed for home, and did not play for the rest of the season.

[25][27] He retired as a player early in the 1988 season at the age of 32, as he was batting .255/.338/.418, due to his arthritic big toe.

A year later, in 1995, Wynegar was named manager of the Charlotte Rangers of the Florida State League, where he remained through the 1997 season.