In Weiss's offensive numbers didn't improve as he battled through injury and adversity even though the A's repeated as AL pennant winners, meeting their crosstown rival San Francisco Giants in the 1989 World Series. Although the Series would be overshadowed by the Loma Prieta earthquake on October 17 which delayed play for ten days, Weiss homered and the A's swept the Giants to claim their first world title in fifteen years. saw Weiss put up his best offensive numbers to date in hits, runs and batting average, while also stealing nine bases. The A's won their third straight pennant, but Weiss was injured in the 1990 American League Championship Series against the Boston Red Sox and missed Oakland's 1990 World Series loss to the Cincinnati Reds, four games to none. Limited by prior injuries, he didn't play much in as the A's missed the playoffs for the first time since 1987. In what would be his final year in Oakland, he hit.212 in and was traded to the new NL expansion Florida Marlins during the offseason. He played in 158 games in for the Marlins, but after the season became a free agent, chose to sign with the Colorado Rockies and was the first player to play for both of these 1993 expansion teams. Weiss spent four modestly successful years with the bat in Colorado, posting career highs in home runs and RBIs ; but his strengths lay in solid defensive play at shortstop and ability to reach base.
Later career
In December 1997, he signed with the Atlanta Braves and became their starting shortstop, hitting.280 and making the All-Star team for the only time in his career in 1998. The Braves finished with 106 wins but lost the NL pennant to the San Diego Padres, but he was slowed by injuries and appeared in less than a hundred games for the first time since 1991. The next season, his decline continued with a disappointing.226 batting average. While with the Braves, Weiss' family had a health scare when his 3-year old son contracted E. Coli from an Atlanta water amusement park which caused his kidneys to shut down. Weiss' son made a full recovery. In Game 3 of the 1999 NLDS against the Houston Astros, however, he made a stunning defensive play to save the season. In the bottom of the tenth, with the bases loaded, one out and the score tied, Tony Eusebio hit a sharp grounder up the middle. Weiss ranged hard to his left, fell on his stomach and threw to home for the force. After the game, he said the ball nearly ripped the glove off his hand. Weiss and the Braves went on to win the game, and with it the division series, on their way to the NL pennant and the 1999 World Series, which they lost to the New York Yankees. In 2000, he only had 192 at-bats, mostly due to losing the starting shortstop job to the emergent Rafael Furcal, who would go on to win Rookie of the Year just like Weiss twelve years prior. He retired after the season.
Post-playing career
Weiss's charitable contributions have included numerous donations to Watertown High School in Watertown, New York. In addition, the baseball field at his alma mater, Suffern High School, is named after him. After retiring from the Braves as a player following the 2000 season, he returned to the Rockies as a special instructor and adviser to the front office from 2002 to 2008. He left that job to spend more time with his family, and coach his sons' baseball and football teams. Weiss was signed on November 7, 2012, to be the manager of the Colorado Rockies. Weiss made the decision to step down as the manager of the Colorado Rockies after four managerial seasons with the club on October 3, 2016. He finished with a record of 283 wins and 365 losses. The Braves announced that Weiss had been hired as bench coach on November 10, 2017.