Scotland insist they followed all Covid-19 protocols and do not know how Billy Gilmour contracted the virus.
The 20-year-old was forced to miss Tuesday’s 3-1 defeat by Croatia — ending Scotland’s participation at Euro 2020 — after returning a positive test on Sunday.
England pair Mason Mount and Ben Chilwell were identified as close contacts of their Chelsea team-mate after a 20-minute conversation in the tunnel at Wembley following Friday’s goalless draw, and they are now in self-isolation.
Billy Gilmour missed Scotland's last game after he tested positive for Covid-19 on Sunday
Ben Chilwell and Mason Mount also had to miss England's game against the Czech Republic
But Scottish FA chief executive Ian Maxwell says nothing more could have been done to avoid Gilmour’s positive test.