He originally signed a contract with the Boston Red Sox that year but that deal got voided. The next year he signed with the Atlanta Braves, but he struggled at 19-23 in their farm system & was released in July of 1980.
A week later he was picked up by the New York Mets. Leach was a side armed throwing pitcher with a unique style. In his pitching motion, he would bend down low scraping his knee, which he kept padded, on the ground. He was 10-3pitching at both AA Jackson & AAA Tidewater for the Mets in 1981, getting called up in August of that year.
He made his MLB debut on August 12th at Wrigley Field with the Mets ahead 4-2 in the 7th inning. Leach blew the save allowing a two run HR to the Hawaiian native Mike Lum.
He would appear in 21 games the rest of the way, going 1-1 with a 2.55 ERA as a reliever with one start, mixed in. In 1982 he began the year at AAA Tidewater getting back to the Met staff by June. He made just one start on the season & it was a memorable one.
The only run of the game was driven in by Hubbie Brooks on a sac fly RBI. It was the 13th one hitter in Mets history up to that point.
On the season Leach was 2-1 with three saves and a 4.17 ERA in 21 appearances. He struck out 30 batters walking 18 in 45 innings of work.
He couldn’t crack thru to the big league club the next two years but had an impressive 11-4 season at AAA Tidewater in 1984 tying Bill Latham for the team lead in victories.
He was back at Shea in 1985 & had another memorable start on August 22nd throwing a three hit shutout against the San Francisco Giants. On the year he was 3-4 posting a strong 2.91 ERA with 30 strike outs in 55 innings. He began the 1986 Mets Championship season with the team but after six games was back at AAA Tidewater where he went 4-4.
He had his best year in 1987 when he got a full time chance to start as the staff was short pitchers first due to Dwight Gooden entering to rehab & second when Bobby Ojeda went down with injury for the rest of the season.
After three straight wins in relief at the end of May Leach was placed in the starting rotation. He won three straight decisions in June all on the road & then tossed a memorable two hit shutout in Cincinnati. That night he beat the Reds to best his record to 7-0. Next Leach earned wins at Atlanta & in Montreal, as well as earning a hold in relief in St. Louis in between starts.
On August 11th at Shea Stadium he beat the Expos again, pitching eight innings allowing two runs, to put him at 10-0 on the year with a 2.80 ERA. Leach was an incredible surprise to the Mets helping them out in a time where they were short. The team fell short of the playoffs finishing second to the rival St. Louis Cardinals.
He finished the year with a record of 11-1 with 61 strikeouts 29 walks in 131 innings pitched and a 3.23 ERA. Leach made 12 starts that year in 44 appearances & finished 12 games. He allowed 14 HRs in that time & 132 hits.
It was back to the bull pen in 1988, where he had another fine season, going 7-2 with three saves while posting a 2.54 ERA. He appeared in three games of the 1988 NLCS, striking out four Los Angeles Dodgers, without allowing any runs in five innings pitched.
In 1989 he appeared in just ten games with New York, playing his last Mets game on June 5th before getting traded to the Kansas City Royals for Aguedo Vasquez.
In his seven year Mets career Leach was 24-9 (.727 %) with three saves 194 strikeouts 104 walks three shut outs three complete games in 18 starts & 176 appearances.
He was released by the Royals in Spring Training 1990 & then signed with the Minnesota Twins. Leach pitched two season in the Twin Cities, going 2-5 with a pair of saves in 1990, making 55 appearances.
In the 1991 Twins Championship season, he made 50 appearances going 1-2 with a 3.61 ERA.
1991 World Series: He did not pitch in the 1991 ALCS win over the Toronto Blue jays. In the World Series he made two appearances. In Game #5 he gave up one run in the 5th inning, of the 14-5 loss to the Atlanta Braves.
After winning his second career Championship, he signed with the Chicago White Sox for 1992, going 6-5 with a 1.95 ERA in 51 appearances. He finished his playing career in Chicago, the following season.
In an eleven year career, Leach was 38-27 in 376 Games pitched with ten Saves, he had 331 Strikeouts with 197 walks and a 3.15 ERA in 700 innings pitched.
Retirement: In 2000 he wrote an autobiography titled: "Things Happen for a Reason: The True Story of an Itinerant Life in Baseball".