Christian Eriksen collapsed during Denmark's friendly against Ukraine but was later able to walk off the field, five years after suffering a cardiac arrest during the European Championship.
The 34-year-old former Manchester United midfielder, who has a type of pacemaker, fell to the ground in the 64th minute of the match in Odense on Sunday.
Medical staff rushed onto the pitch while players from both teams gathered around him to shield the scene from television or smartphone cameras.
The referee called off the match with Denmark leading 2-1 and Eriksen was subsequently taken to hospital, having been shielded by both sets of players as he walked off the pitch.
"Christian Eriksen is conscious and doing well under the circumstances," the Danish football association wrote on social media.
Eriksen has worn a type of pacemaker since he collapsed during the group stage game against Finland at Euro 2020, which was played in 2021.
That led to him spending more than six months away from football.
Denmark's team doctor Morten Boesen said Eriksen was "doing well".
"As I see it, the pacemaker responded as it should," he said.
"He was briefly unconscious, but regained consciousness very quickly, and we were quickly in contact with him.
"He will now undergo further examinations at the hospital to determine what caused the incident.
"We are in ongoing contact with him and the doctors at the hospital.
"But Christian is doing well and he asked me to send his regards to all the players and tell them that he was OK."
Denmark captain Pierre-Emile Hojbjerg praised the swift help his team-mate received.
"There was a throw-in and I walked calmly to the touchline. Then I turned around and I saw Christian collapse," he told Danish television station TV2.
"We know very well what that means and the reaction was extremely rapid and respectful."
Denmark coach Brian Riemer, who worked with Eriksen at Brentford, said it had been "an extremely shocking experience for everyone, the staff, the players and the opponents".
He said: "He's someone who counts a lot for me. You're closer to certain players than others and he was one of the ones I got close to at Brentford."
- 'Really awful' -
When Eriksen suffered his cardiac arrest at Euro 2020, the match resumed, with Finland winning 1-0.
Eriksen continued his career seven months later at Brentford in the Premier League, having been forced to leave Inter Milan because of Italy's rules against playing with a pacemaker.
He went on to join Manchester United, where he won the FA Cup and League Cup, and now plays for Wolfsburg in Germany, where he has another year to run on his contract.
He also returned to international football, playing for Denmark at the 2022 World Cup in Qatar and Euro 2024 in Germany.
Denmark have not qualified for the World Cup in North America, which starts next week.
Former Denmark striker Nicklas Bendtner said the latest incident had been "really awful" but was relieved Eriksen was conscious.
"The main thing is that he was able to walk off by himself because that makes you think he's doing OK given the circumstances," Bendtner told TV2.
"But these are terrible images that outweigh the rest of the evening.
"It's the second time it's happened and as a friend of Christian's, it's really awful."
