Drafted by the White Sox in the fifth round of the 1966 Major League Baseball draft after graduating from Marion High School, the 6 ft (1.8 m), 190 lb (86 kg) Frailing spent seven seasons in the ChiSox farm system before his recall in the closing weeks of the 1972 season.

However, his success in the minor leagues that season — he won 11 of 14 decisions with a stellar 2.86 earned run average and was named to the official American Association All-Star Team[1] — attracted the attention of the crosstown Cubs who acquired Frailing along with Steve Stone and Steve Swisher from the White Sox for Ron Santo on December 11, 1973.

[3] Frailing made the 1974 Cubs' Major League roster and appeared in 55 games as a "swing" man, making 16 starts and compiling a 6–9 record and a 3.88 earned run average in 125+1⁄3 innings pitched.

On May 27, he registered his only MLB complete game, a 12–4 triumph over the San Francisco Giants at Wrigley Field, despite surrendering 15 hits.

He began 1976 in promising fashion, with only one earned run allowed in his first 14+2⁄3 innings pitched, but a lingering shoulder injury[5] shut him down and effectively ended his career.