Elster was drafted by the New York Mets in the second round of the January draft out of Golden West College in Huntington Beach, California. He batted .269 with fourteen home runs and 135 runs batted in over three seasons in the Mets' farm system when he received a somewhat surprising September call up to the majors in with the Mets on the verge of capturing the National League East. He made his major league debut as a late inning defensive replacement on September 2 against the San Francisco Giants, and got his first major league hit in his first major league at bat the following day. Over the remainder of the season, Elster batted .167 with three runs scored. He had one extra base hit, a double off the Philadelphia Phillies' Kevin Gross. He appeared in four games of the 1986 National League Championship Series against the Houston Astros, and game six of the World Series against the Boston Red Sox. In four postseason at bats, he had no hits.