Geren was drafted by the San Diego Padres in the first round with the 24th pick of the 1979 draft.After spending ten years in the minor leagues, he made his major league debut for the New York Yankees in 1988, playing with New York through 1991.
He spent the first two seasons backing upDon Slaught。In 1990, he had his statistically best season as the starting Yankees' catcher. In 110 games, he had a .213平均成功率8全垒打和31打点。[ 1 ]
2011年5月，Geren的管理风格受到审查的湾区新闻当投手布莱恩·弗恩特斯criticized Geren's communication style after he was replaced as the A's closer amid poor performance in the role.Fuentes later apologized to Geren for going public with his comments, and A's ownerLew Wolffendorsed Geren as the A's manager.Geren's last game as manager was June 9, 2011.
On October 14, 2011, the纽约大都会队hired Geren to be the team's new bench coach replacing former bench coachKen Oberkfell。During the 2015 season, the Mets won theNational League Championship Seriesand played in the World Series against the堪萨斯城皇家队。The Royals eventually won the2015 World Seriesin five games.During his time with the Mets, Geren was praised for his "statistical aptitude" and "strong working knowledge of advanced analytics."Mets General Manager Sandy Alderson also complimented Geren for being "tuned into analytics."
On December 2, 2015, it was reported that the洛杉矶道奇队hired Geren to be the team's new bench coach serving under new manager戴夫·罗伯茨and replacing former bench coach瓦拉赫。Geren said his decision to leave the Mets for Los Angeles was fueled by a desire to be closer to his family in Southern California.During the 2016 season, Geren coached under manager Dave Roberts, who would go on to win the 2016 National LeagueManager of the Year Award。[ 17 ]2017，道奇队赢得了国家联盟冠军系列赛和对阵休斯顿太空人队在世界系列。[ 18 ]