Stafford struggled in the 2013 season as he threw several interceptions, which cost his side matches as they missed the playoffs under former head coach Jim Schwartz.
Caldwell told the TheMMQB.com: "The great majority of poor throws — people look at the arm, and that's important obviously, but I think footwork is the key. I can pull up any gamefilm and show you how our footwork drills help you.
"In a nutshell, the feet and eyes work together. If I'm throwing in a particular direction, my footwork is pointing in the same direction — directly at the target. We'll work on it with Matthew, and he will do them flawlessly."
Caldwell has previously worked with Super Bowl-winning quarterbacks Peyton Manning and Joe Flacco.