كتب : Omar AbdelAziz
Lehmann inexplicably stamped on the foot of Mainz striker Aristide Bance in the final minutes of Sunday's game, allowing the hosts to equalize from the spot.
The 40-year-old, who was sent off in the incident, was also involved in a row with a supporter prior to his exit from the stadium.
He will now miss Bundesliga games against Hoffenheim, Wolfsburg and Bochum.
Apart from that, Stuttgart said Lehmann has sustained a knee-ligament strain in the game at Mainz.
The German giants are facing a tough battle against relegation this season as they lie 15th on 13 points.