Ben Chilwell, Dael Fry and Josh Onomah have withdrawn from the England U21 squad for the Euro 2019 qualifier against Ukraine due to injury.
Details of the injuries sustained by Leicester left-back Chilwell, Middlesbrough defender Fry and midfielder Onomah, who is on loan at Aston Villa from Tottenham, were not revealed by the Football Association on Monday lunchtime.
England currently top Group 4 in qualifying following three wins and a draw from their opening four fixtures, leaving them four points ahead of second-placed Scotland, albeit having played a game more.
Ukraine, meanwhile, remain unbeaten but are down in fourth position after one victory and two draws from their three games. After facing the Three Lions, they take on Scotland at St Johnstone's McDiarmid Park next Tuesday.
England U21s' boss Boothroyd has three new faces in his squad for the game after including Chelsea defender Jake Clarke-Salter, Manchester United's Axel Tuanzebe and Norwich forward James Maddison.
Their call-ups came after U21 regulars Joe Gomez, Ruben Loftus-Cheek and Tammy Abraham were named in Gareth Southgate's senior squad for their games with Germany and Brazil at Wembley.