Siem de Jong has been diagnosed with a collapsed lung and will miss roughly six weeks. The Ajax midfielder will spend the next couple days in the hospital.
De Jong went to the doctor on Monday after experiencing some chest tightness and was told he had a collapsed lung. The lung now has to be drained before it can begin to heal.
Amazingly, de Jong played in Ajax's first two matches of the season and scored in each. It is unclear when de Jong suffered his collapsed lung, but he showed no ill effects in either match, although it is possible that he was playing with the problem in both.
De Jong will miss Sunday's clash with rivals Feyernoord, but if he returns in six weeks he will be back when Ajax take on PSV Eindhoven on September 22. The injury will also rule him out of the Netherlands' two World Cup qualifiers in early September, although he is hardly a key cog in the Dutch team and with a seven-point cushion atop Group D, they should be just fine.