Ajax midfielder Abdelhak Nouri is "out of danger" after collapsing during a friendly on Sunday (AEST), the Dutch club said.

Nouri, 20, was taken to the hospital after laying down on his back in clear discomfort during a friendly with Werder Bremen in Austria.

Ambulances entered the playing area and paramedics tended to Nouri before a trauma helicopter arrived and the match was abandoned, with fans asked to leave the stadium.

After initially saying the Dutchman was in a stable condition, Ajax provided a further update on their return to Amsterdam, tweeting: "Latest update on Nouri: he is on intensive care and kept asleep, but he's out of danger."

Earlier, the club revealed "there was talk of heart rhythm disorders" as the reason for the collapse.

Nouri made his Eredivisie breakthrough with Ajax last season, featuring nine times for the first team under Peter Bosz.

But it was with Jong Ajax where he truly shone in Netherlands' second-tier Eerste Divisie, scoring 10 goals and supplying 11 assists in 26 matches for Marcel Keizer's side.