Ajax player Abdelhak Nouri received treatment on the field after collapsing during Saturday's friendly against Werder Bremen in Austria, with the Eredivisie club describing the situation as "serious".
"Emergency services are still [treating] Nouri, players look anxious", Ajax tweeted.
The 20 year old midfielder was immediately transported to the hospital to receive the necessary medical care.
Werder Bremen, who had been leading the match 2-1, conveyed their best wishes to Nouri, his family and Ajax via Twitter and added that their own players were receiving psychological treatment.
Ambulances and paramedics then tended to Nouri on the pitch, with a screen drawn around him.
Venezuelan opposition figure Leopoldo Lopez granted house arrest due to health problems
Mr Maduro, who for years refused to pardon Mr Lopez, has described him as a risky terrorist who sought to overthrow him through street violence.
Blue sheets were used to shield the fans from the distressing incident, with Nouri having come on at the start of the second half.
"There was talk of hearth rhythm disorders".
"Nouri is now [being] flown by helicopter to hospital. He is stable [and] has [a] heart rate", Ajax tweeted.
Ajax have given an update on Nouri's health, with the player said to have suffered from arrhythmia.
Nouri, who has represented the Dutch national team at all youth levels from under-15 to under-19, is not related to Werder Bremen's coach Alexander Nouri.
- Mother and three children die in Bolton house fire
- Kalyani Priyadarshan Signs Akhil's Movie!
- USA bombers fly over Korean Peninsula after North Korea missile test
- British Columbia Declares State Of Emergency As Nearly 140 Wildfires Ravage Province
- No booze today: fed-up Mongolians elect new president
- The Ulta Beauty (ULTA) Earning Positive Press Coverage, Study Shows
- Wimbledon: No. 1 Anglique Kerber rallies to hold off Shelby Rogers
- Knicks Sign Issue Sheet with Tim Hardaway Jr. for $71 Million
- Jay-Z Jewish lyric spurs criticism from ADL
- Price For New York-New Jersey Rail Tunnel Rises To $12.9B