England back-row forward Billy Vunipola will have a scan on Monday to determine the severity of the ankle injury he sustained in the win over Ireland.
The Saracens number eight was withdrawn after 35 minutes of the victory over the Irish at Twickenham and replaced by Ben Morgan.
The RFU confirmed Vunipola will be sent for a scan after the weekend 'to assess any damage'.
Flanker Tom Wood was replaced in the 70th minute after suffering cramp but the Northampton man has now recovered.
The matchday 23 will return to Pennyhill Park late on Tuesday morning and, following a review of the Ireland match and training, the replacements will return to their Aviva Premiership clubs.