Northampton Saints number eight Gerrit-Jan van Velze has been cited for an alleged tip tackle in Sunday's Premiership win against Exeter Chiefs at Franklin's Gardens.
Van Velze received his marching orders in the 38th minute of the 24-21 triumph after the television match official was called into action and told referee JP Doyle to issue a yellow card for the challenge on Exeter scrum-half Will Chudley.
This was the South African's second sin-binning in as many matches for Northampton since joining from the Blue Bulls during the off-season.
He was also yellow-carded during Saints' 24-19 win over Gloucester at Kingsholm last week.
Van Velze will find out the RFU's verdict on the Exeter incident at a hearing on Tuesday.