Arizona Diamondbacks (2001–06) He played for the Diamondbacks
2001 World Series championship team, for which he was 0–1 with a 3.60 ERA, but was not on the World Series roster. In , Koplove was 6–1 with a 3.36 ERA in 55 games, giving up only 47
hits in 61.2 innings (holding batters to a .213
batting average and a .276
slugging percentage; with men on base he was even stingier – .207/.228). In games that were late and close, he held batters to a .188 batting average. In , Koplove was 3–0 with a 2.14 ERA in 31 games. With runners in scoring position, he held batters to a .100 batting average, and a .133 slugging percentage, and he held the first batters he faced to a .074 batting average. In 2004, Koplove set career highs in appearances (76), innings pitched (86.2), strikeouts (55), and saves (2), but his ERA was at 4.05.
Cleveland Indians (2007) In March 2007, the
Cleveland Indians agreed to terms with Koplove on a minor league contract. On May 23, the team called him up from the Triple-A
Buffalo Bisons. He was 2–0 with 3 saves and a 1.00 ERA in 17 relief appearances (18 innings, 15 hits, 2 earned runs, 8 walks, 14 strikeouts). He limited batters to a .224 average and a .111 average with runners in scoring position. In , with the Buffalo Bisons he was 4–2 with 14 saves and a 2.50 ERA in 51 relief appearances.
Los Angeles Dodgers organization (2008) After becoming a minor league
free agent following the conclusion of the 2007 season, Koplove signed a minor league contract with an invitation to spring training with the Los Angeles Dodgers on December 12, 2007. He pitched the entire year for the Dodgers Triple-A affiliate, the
Las Vegas 51s. He was the only American pitcher not to give up a hit; he pitched innings in four appearances, and struck out six.
Philadelphia Phillies organization (2009) Koplove was signed by the Philadelphia Phillies to a minor league contract after the 2008 season, and was invited to spring training as a non-roster invitee. On June 1, 2009, Koplove exercised a clause in his contract that stated if he was not on the major league roster by June 1, he would be granted his outright release.
Pittsburgh Pirates organization (2009) On June 6, 2009, Koplove signed a minor league deal with the
Pittsburgh Pirates, and was assigned to the
Indianapolis Indians, also in the International League.
Seattle Mariners organization (2009–10) On August 4, 2009, the Pirates traded Koplove to the
Seattle Mariners for minor league shortstop Deybis Benitez. He was granted free agency in November 2009. On December 22, 2009, Koplove signed a minor league contract with the Seattle Mariners. On July 1, 2010, Koplove was released by Seattle.
San Diego Padres organization (2010–11) The Padres signed Koplove in August 2010, and re-signed him in February 2011. However, he didn't make the spring training roster and was cut in March 2011.
Camden Riversharks (2011) He signed with
Camden Riversharks of the Indy league in April 2011. He filed for free agency hoping to sign on to a new team. ==Scouting career==