The 22-year-old, who will play for his club in Saturday’s Super League Grand Final against Warrington, will help plug the gap caused by the withdrawal of Sam Burgess, who is due to undergo shoulder and wrist surgery.
In bringing in a specialist outside back for a back-row forward, Bennett clearly intends to switch Wigan’s John Bateman from the makeshift centre spot he occupied throughout the 2017 World Cup to his customary slot in the second-row.
Gildart, who was Super League’s young player of the year in 2017 and turned down the chance to play for Italy in the 2017 World Cup, is the fourth player to be promoted from the England Knights squad set to tour Papua New Guinea later this month.
He is one of six uncapped players in Bennett’s squad, which stands at 23 following the withdrawal of Castleford scrum-half Luke Gale with a knee injury that requires surgery.
England play France at Leigh next Wednesday and, with nine of Bennett’s squad playing in Saturday’s title-decider at Old Trafford, the coach has been left with just 14 players for that game.
England say they will announce a replacement for Gale early next week.
Castleford and England head physio Matt Crowther said: “Luke unfortunately has some cartilage damage from the trauma suffered to his patella during the Wakefield game which kept him out for months.
“Due to the extent of the injury, he needs surgery this week which will be beneficial for player, club and country long term.”
Gale, who started every match in the 2017 World Cup, said: “Obviously I am gutted to have to withdraw. I am so proud to represent my country but right now I need to do what’s best to get my knee right and give me a good pre-season to ensure I can give my club my best in 2019.”
Gildart’s place in the Knights squad goes to Salford full-back Niall Evalds and coach Paul Anderson has also called up Warrington’s former Hull FC winger Tom Lineham as a replacement for Castleford’s Greg Minikin, who has withdrawn because of injury.