Lewis Gregory, the Somerset allrounder, will captain the England Lions in their four-day game against Australia A which starts at Canterbury this Sunday.
Gregory, who was called into England's first ODI squad after the 2015 World Cup but did not make the final XI in the one-off game against Ireland, is the leading wicket-taker among Division One seamers this year, with 44 wickets at 13.88 in his eight games.
He has some captaincy experience, having skippered England's under-19s back in 2011, and will again lead Somerset in their upcoming Vitality Blast campaign after taking over from Jim Allenby last year.
Gregory is realistically an outside bet for Ashes selection given England's catalogue of seam-bowling allrounders, but can hope to force his way into their T20I plans ahead of this winter's tours to New Zealand and South Africa.
Curran, who has taken 18 wickets in his four Championship games for Surrey since returning from the IPL, replaces Saqib Mahmood, after the Lancashire fast bowler suffered an abdominal problem during their game at Northampton this week.
Hain's call-up comes immediately after his twin hundreds for Warwickshire secured a draw against Hampshire. He is included after Ben Duckett's groin injury in Nottinghamshire's defeat at Somerset.
Jack Leach, Ben Foakes, and Curran are the three Test players in the squad, and all will look to press cases for Ashes selection.
Australia A warmed up for this game with a ten-wicket thrashing of Sussex at Arundel, in which both openers - Marcus Harris and Joe Burns - made centuries. Both men are in contention to open the batting with David Warner this summer.
England Lions: Lewis Gregory (captain), Jack Leach (both Somerset), Sam Hain, Dom Sibley (both Warwickshire), Sam Curran, Ben Foakes (both Surrey), Sam Northeast (Hampshire), Jamie Porter (Essex), Zak Crawley (Kent), James Bracey (Gloucestershire), Ollie Robinson (Sussex).