Sauer played college football at the University of Minnesota.[1] He was selected in the sixth round (188th overall pick) of the 1996 NFL draft by the Atlanta Falcons.[2] He ended up playing more NFL games than all but 12 of the 87 players taken in the last two rounds of that year's draft. As a rookie in 1996, Sauer played in all 16 games for the Falcons, but only started one. He had seven tackles, four assists and one forced fumble that season.[1] In 1997, he once again played in all 16 games and started one. He had eight tackles, one assist and one fumble recovery for the season.[1]
In 1998, he played all 16 games again, and started six, primarily at right linebacker, as the Falcons went on to win the National Football Conference championship and play in the Super Bowl.[1][3] He set a career high with 29 tackles, and also had five assists and his only career interception, and got to play in Super Bowl XXXIII.[1][4] In 1999, he again played all 16 games for the Falcons, starting three. He had 18 tackles, six assists and his only career sack.[1]
Sauer joined the Minnesota Vikings for the 2000 season. In what would be his final NFL season, he played in nine games for the Vikings. He did not start any games, and had only one tackle for the season.[1]