The New York Rangers drafted hulking blue liner Scot Kleindorst in the middle of his four-year stay with Providence College. Kleinendorst was a Second Team All-Star during his draft year, and was a First Team All-Star during his final season before joining the Untied States for the 1982 World Championships.
In 1982-83 he played his first full season as a pro and spent just 10 games in the minors with the rest of his time being spent in the NHL with the Rangers. Kleinendorst chipped in two goals and 11 points for the Blueshirts and also contributed two assists during six playoff games in a successful rookie campaign. The following year he was limited to just 23 games in New York, while again playing 10 games at the minor league level and nursing some injuries. In February of that year the Rangers used Kleinendorst as bait to acquire some scoring punch when they dealt him to the Hartford Whalers in exchange for Blaine Stoughton.
During his first season with the Whalers Kleinendorst again split his time between the NHL and the minor leagues though he became a full time NHLer in 1985-86. With his minor league days behind him, Kleinendorst was unable to shake another part of his Ranger past, injuries. He played 41 games for Hartford in '85-'86 and was also in the lineup when they swept the Quebec Nordiques in the first round of the playoffs that spring, their first-ever playoff series victory. In 1986-87 Kleinendorst enjoyed the most productive, and healthy, year of his career. He was on the blue line for the Whalers in 66 games and had career highs in all offensive categories with three goals, nine assists and 12 points. Injuries limited him to just 44 games the following season then he suffered through a tough campaign in 1988-89.
Kleinendorst played 24 games in Hartford but was only able to contribute one point. Injury woes and a trip to the minors led to the Whalers deciding that they had seen enough of the big defenseman. On March 6, 1989 the Whalers dealt him to Washington for Jim Thompson.
He played three games for the Capitals to close out that year then the following year he began the most frustrating, and final, year of his career. Kleinendorst began the season healthy, but in the end he played just 17 games that entire year, with two of them coming in the minors. He managed to score a goal and three assists for the Capitals, but after suiting up for three games in the playoffs for Washington, he finally gave his battered body a break and retired from the game.