Ayala went to high school at Rio Mesa in Oxnard, California. He was brought up with the Reds as a starter before moving to the bullpen in his second season. The Reds traded Ayala with catcher Dan Wilson to the Mariners for Bret Boone and Erik Hanson in November 1993.
Ayala finished the strike-shortened 1994 season with a 2.86 ERA and 71 strikeouts in 57 innings while saving 18 games. He earned a career-high 19 saves during the Mariners' "Refuse to Lose" 1995 season.
On April 24, 1996, Ayala suffered a severe hand laceration trying to open a Chicago hotel window.[1]
In 1998, Ayala struggled to a 7.29 ERA over 62 games with a 1-10 win-loss record over his appearances. He accrued a -2.1 WAR which would be the worst of his career. In an ESPN article senior writer Jim Caple later listed Ayala as one of the Mariners' "Hometown Bums", noting he finished the season having blown more saves (9) than games saved (8).[2]
The Mariners traded Ayala to the Montreal Expos for minor leaguer Jimmy Turman on April 3, 1999, with Seattle paying all of Ayala's $1.8 million salary that year. Montreal released him a few months later and he finished the season pitching for the Chicago Cubs.
The Minnesota Twins signed Ayala as a free agent, making him a non-roster invitee for the 2000 season. They released him before the start of the regular season.
He started the regular 2000 season pitching for the Triple-A Iowa Cubs, but after starting 1–2 with a 4.61 ERA, was released on May 8.
On May 18, he signed with the Los Angeles Dodgers' Triple-A affiliate, the Albuquerque Dukes. Two months and nine saves later, the Dukes released him.
