Jack Van Plutofriette was called by the British and Ireland Lions ahead of his match against Argentina in Dublin on Friday.
Van Poortvliet, 24, will add a scrum half cover later this week to prepare tourists for a warm-up match. Leicester No. 9 was responsible for club duties in the Gallagher Premiership Finals and was part of the England team for a match against France XV on Sunday.
The three Scrum Harves currently on the team are Jamison Gibson-Park, Alex Mitchell and Tomos Williams. The Lions say Van Plutofriet will be taking part as a “cover” for a match against Argentina the day after saying there is a team that is perfectly suited to Friday’s match.
Van Poortvliet has 15 England caps and made his Test debut in 2022.