 The Houston Astros drafted Siebert in the third round of the 1971 Major League Baseball Draft (58th overall, 7 ahead of Ron Guidry) out of Edina High School in Edina, Minnesota.He went 36-24 with a 2.86 earned run average over three seasons in Houston's farm system when he received a September call-up in .He started in his major league debut on September 7 against the San Diego Padres, and exited after seven strong innings with a 4-2 lead the bullpen was unable to hold.