Christian Eriksen is in a stable condition after suffering what doctors said was a cardiac arrest during Denmark’s opening Euro 2020 match on Saturday.

The Danish footballer is awake in hospital, and has “sent his greetings to his teammates” while he remains under examination following his collapse in Copenhagen.

Denmark team doctor Morten Boesen told a news conference that tests on the player “so far look fine”, adding that Eriksen “was gone” before resuscitation efforts began.

Mr Boesen added: “How close were we? I don’t know. We got him back after one defib, so that’s quite fast.”

“We don’t have any explanation why it happened. The details about what happened I am not quite sure of because I am not a cardiologist, I will leave that to the experts. I didn’t see it live, only on screens afterwards.”

Earlier on Sunday, the Danish FA said in a tweet that the 29-year-old had been in contact with the squad on Sunday, as he continues to recover from the incident in Copenhagen.

“This morning we have spoken to Christian Eriksen, who has sent his greetings to his teammates,” it said. “His condition is stable and he continues to be hospitalised for further examination,” it added.

Denmark‘s players and staff have “received crisis assistance and will continue to be there for each other after yesterday’s incident”, the statement added, with some of Eriksen’s teammates having been reduced to tears as they formed a wall around him to shield him from the cameras while he received treatment on the pitch.

“We would like to thank everyone for the heartfelt greetings to Christian Eriksen from fans, players, the royal families from both Denmark and England, international associations, clubs etc,” the statement said.

Medics attended Eriksen after being quickly ushered on to the field by English referee Anthony Taylor, while Denmark captain Simon Kjaer made what has been hailed as a life-saving intervention by securing his neck, clearing his airways and starting CPR.

Kjaer then led the Danish players in forming the ring around their teammate and comforted Eriksen’s partner, who appeared distraught as she went on to the pitch.

Inter Milan midfielder Eriksen, who spent seven years in English football with Tottenham, has been inundated with messages of support since his collapse – including footballers past and present, pundits, politicians and royals.

Boris Johnson was said to have been “shocked” by what happened.

“He is very thankful for the quick thinking actions of officials,” the prime minister’s spokesman said. “The response of players and fans in the stadium was exemplary. It showed sport at its best.”

The Duke and Duchess of Cambridge also tweeted to praise the referee and medical team.

Prince William, who is also president of the FA, added: “Encouraging news about Christian Eriksen, we are all thinking about him and his family.”

Also among those to send their well-wishes was former Arsenal and Birmingham player Fabrice Muamba, whose heart stopped for more than an hour while playing for Bolton against Spurs in 2012.

Dr Jonathan Tobin, the Bolton club doctor at the time, told Sky News: “Even managing to start CPR under that much pressure… I’m not understating it when I said I could hardly breathe when I first started treating Fabrice on the pitch.

“After a minute or two, I was into the groove, everything was fine, but that first minute it was hard. All I could hear was my own heart thundering in my head.”

“So, congratulations for starting the CPR and congratulations for letting their training take over,” he said of those who treated Eriksen.

Muamba hoped to resume his career but retired from professional football five months later on medical advice – and doctors are concerned that Eriksen may also struggle to play again.

Sanjay Sharma, professor of sports cardiology at St George’s University in London, who worked with Eriksen at Tottenham during his time in north London, said: “The good news is he will live, the bad news is he was coming to the end of his career, so would he play another professional football game? That I can’t say.

“In the UK he wouldn’t play. We’d be very strict about it.”

He added: “Without putting it too bluntly, he died today, albeit for a few minutes, but he did die and would the medical professional allow him to die again? The answer is no.”

Inter physician Piero Volpi told The Associated Press now was not the time to be making such assessments.

“Right now, the important thing is that he recovers,” added Dr Volpi, who also confirmed that Eriksen had never contracted COVID-19. He also was yet to receive a vaccine.

Some Denmark players chose not to continue playing, coach Kasper Hjulmand said after the Group B match, which Finland went on to win 1-0 via a 59th minute goal from Joel Pohjanpalo.

Eriksen was the focus of further well-wishes at Wembley in London on Sunday afternoon, when England begin their Euro 2020 campaign against Croatia.

England captain Harry Kane is a former teammate of Eriksen during his time at Tottenham.