It's a homecoming of sorts for Knapp, 48, who held the same job with the Raiders from 2007-08.
Knapp left Oakland to serve as offensive coordinator for Seattle in 2009 before moving on to Houston. He has spent the past two seasons as quarterbacks coach for the Texans.
With Knapp helping to guide the passing attack in 2011, the Texans won the first AFC South division title in franchise history and earned their first postseason victory.
While leading the Falcons' offense from 2004-06, Atlanta led the NFL in rushing with 169.9 yards per game.
Knapp's first chance to be an NFL offensive coordinator came in 2001 with San Francisco. During Knapp's three years in that position, the 49ers ranked fifth in the NFL with an average of 355.8 yards per game.
Knapp got his start in the NFL serving as quality control assistant with the 49ers from 1995-97, then was promoted to quarterbacks coach in 1998.