Saracens prop Mako Vunipola has received a three-week ban for dangerous play following his red card against Newcastle Falcons on Sunday.
Vunipola, 31, could reduce his ban by one week if he completes a World Rugby Coaching Intervention Programme.
That would enable him to be available for England's autumn internationals.
England are set to play Argentina, Japan, New Zealand and world champions South Africa in November.
Vunipola admitted the charge of dangerous play, accepting he had made direct contact with the head of Falcons full-back Tom Penny and apologised for the action which he said was unintentional.
As it stands, Vunipola is set to miss Saracens' Premiership home game against Bath on Saturday, and the visit of London Irish in the Premiership Cup two days later. Providing he completes the coaching programme, Vunipola could feature in the Premiership trip to Exeter on 22 October.
The independent disciplinary panel also handed a three-week ban to Wasps full-back Jacob Umaga for "tackling, charging, pulling or grasping the jumper in the air" after he was sent off against Northampton Saints.
Umaga was shown a red card in the 66th minute of Wasps' 40-36 defeat for tackling Saints winger Courtnall Skosan in the air in a challenge that left Umaga unconscious in the aftermath.
The games Umaga will miss will be determined when he his fit enough to return to playing.