Joe Marler will miss England's opening two NatWest 6 Nations matches after he was handed a six-week ban following a red card in Harlequins' Aviva Premiership defeat at Sale.
Marler was sent off for striking TJ Ioane with the shoulder as Harlequins lost 30-29 to the Sharks at the AJ Bell Stadium in Salford on Saturday.
An independent Rugby Football Union (RFU) disciplinary panel convened in London on Tuesday evening, when Marler pleaded guilty to the charge.
The Quins prop will serve his suspension until February 20, ruling Marler out of both the away match to Italy and the Twickenham clash with Wales.
Marler, who missed England's autumn international with Argentina due to a three-week suspension, will be free to return to action for the Calcutta Cup clash against Scotland at Murrayfield on February 24.
Chairman of the independent disciplinary panel Philip Evans QC said: "The panel found that contact was made with the head of TJ Ioane and as a result the mandatory entry point is mid-range.
"The panel considered that the player's previous record was such that it required an additional period of suspension of one week.
"However, because of his plea, his conduct since the incident took place and other personal mitigation, the panel allowed some reduction."
Samoa flanker Ioane, meanwhile, had also found himself cited following the incident for striking Marler with his arm, and was handed a two-week suspension.
The matter was dealt with on papers, with Ioane pleading guilty to the charge, the RFU confirmed.
Ioane will be able to play again on January 23, so must sit out two European Rugby Challenge Cup matches.