Education
He attended high school in Redmond, Washington and was a standout pitcher in college for the Washington State Cougars under coach Bobo Brayton.
He attended high school in Redmond, Washington and was a standout pitcher in college for the Washington State Cougars under coach Bobo Brayton.
He left school before completing his senior season. He is a native of Saint Louis Park, Minnesota. Niedenfuer played for the Los Angeles Dodgers, the Baltimore Orioles, the Seattle Mariners and the Saint Louis Cardinals and was exclusively a reliever during his 10-year career, which began in the strike-shortened 1981 season
As a rookie in 1981, he appeared in only 17 games for the Dodgers, but he excelled in the 1981 World Series, pitching five innings in two games and allowing no runs as the Dodgers defeated the New York Yankees.
His best all-around year was 1983, when he pitched in a career-high 66 games and posted an 8-3 record with 11 saves and a 1.90 earned run average.
In 1985 he went 7-9, but posted career highs in saves with 19 and innings pitched with 106.1 with a fine 2.71 European Research Area. In the 1985 National League Championship Series, he gave up a walk-off home run to Ozzie Smith in Game 5 that gave the Saint Louis Cardinals a Game 5 victory over the Dodgers. In 1987, during his seventh season with the Dodgers, he went 1-0 with a 2.76 European Research Area in 15 games before being traded to the Baltimore Orioles.
He struggled in the American League the rest of the season, with a 4.99 European Research Area in 45 games. He improved in 1988, posting a 3.51 European Research Area with 18 saves.
After the 1988 season, he became a free agent, spending one season each with the Seattle Mariners and Saint Louis Cardinals, going a combined 0-9 before retiring following the 1990 season with 484 career games pitched.