The 27-year-old was cited after being shown a yellow card for hitting lock Will Rowlands with his elbow at the Ricoh Arena.
While an independent panel deemed that Marler actually hit the second-row with his arm, it was still considered an action worthy of a red card.
The front-rower will therefore miss England's first two Autumn Internationals, against Argentina on November 11 and Australia on November 18.
Tournament organisers European Professional Club Rugby said in a statement: "The committee upheld the citing complaint and determined that the offence had warranted a red card, but decided after consideration that the strike by the player was with the arm rather than the elbow.
"In deciding that Marler is suspended until midnight on Sunday, November 19, the Committee took into account the player's likely playing commitments in the coming weeks. Both Marler and EPCR have the right to appeal the decision."
Marler has featured regularly for England since making his debut in 2012 and has been capped 51 times.