Christian Eriksen had collapsed to the ground during Denmark's first game of Euro 2020 against Finland, and had to receive CPR.
Wales will take on Denmark in the first match of Euro 2020 knockout stage at Amsterdam on Friday.
Denmark beat Russia 4-1 at Copenhagen on Monday night to qualify for the last 16 of Euro 2020 from Group B behind Belgium as the runner-ups.
Denmark take on Belgium at Copenhagen in the Euro 2020 Group B second round fixture.
Eriksen is Denmark's most active capped player with 108 caps as well as the team's top goalscorer with 36 goals.
Eriksen had lost consciousness for quite a while, as the players and fans waited nervously for an update which UEFA gave a few moments later.