Frost made his MLB debut on September 11, 1977, against the California Angels at
Anaheim Stadium. He turned in a quality start, pitching 6
innings and giving up just two
earned runs. He
struck out three,
walked none, and received a no decision in the 5–4 White Sox loss. His first big league
win came a week later in another start against the Angels, this time at
Comiskey Park. He went 7 innings, gave up three runs, and won 7–3. Frost was traded along with
Brian Downing and
Chris Knapp to the Angels for
Bobby Bonds,
Richard Dotson, and
Thad Bosley on December 5, 1977. He split time between the
Salt Lake City Gulls of the
Pacific Coast League and the big leagues in 1978, and went 5–4 with a 2.58
earned run average (ERA) in 11 games (ten starts) for the Angels. Frost had his biggest year in 1979. He won 16, lost 10, and led Angels starters in ERA (3.57),
winning percentage (.615), and
innings pitched (239). California had an impressive group of starters that year, including Frost,
Nolan Ryan,
Don Aase,
Jim Barr,
Chris Knapp, and
Frank Tanana. They ultimately won the
American League West Division pennant that year with an 88–74 record. Elbow problems severely limited Frost's effectiveness for the remainder of his career. In the next three seasons (two with the Angels and one with the
Kansas City Royals) he was a combined 11–22 with a 5.43 ERA. Frost's career totals for 99
games pitched include a 33–37 record, 84
games started, 16
complete games, 3
shutouts, 1
save, and 7
games finished. He allowed 251 earned runs in 550 innings pitched, giving him a lifetime ERA of 4.10. His career highlights include a four-hit, no walk complete game shutout vs. the
Oakland A's (July 3, 1979), an eight-strikeout, no walk complete game win (10–1) vs. the
Baltimore Orioles (July 7, 1979), and a ten-inning, four-hit complete game win (2–1) vs. the
Minnesota Twins (April 16, 1980). ==Later life==