After going undrafted in the 1980 Major League Baseball Draft, he signed with the Kansas City Royals as an amateur free agent.

After four seasons in the minors, in which he compiled a 20–15 record with 49 saves and a 2.29 earned run average, Huismann made his major league debut on August 16, 1983 against the Detroit Tigers.

He made it in time to enter the game in the fifth inning, and with runners on first and third and two outs, Huismann induced a fly ball to center from cleanup hitter Lance Parrish to end the threat.

He made his only post season appearance in game one of the 1984 American League Championship Series against the Detroit Tigers.

Instead, he compiled an American Association record 33 saves for the Omaha Royals to earn the league's Most Valuable Pitcher Award.