PSV Eindhoven duo Jefferson Farfan and Ibrahim Afellay are recovering after suffering head injuries in the weekend's win over Feyenoord.
Farfan (pictured) scored the game's opening goal in the 2-1 win at the Philips Stadion, which took PSV up to sixth.
The attacker was left with heavy concussion after an unfortunate collision with team-mate Patrick Kluivert.
Midfielder Afellay had already been taken off in the first half after being hit by a Pierre van Hooijdonk free-kick.
While Afellay is expected to be fine, it looks unlikely that Farfan will make it back in time for the club's important UEFA Champions League tie against Bordeaux on September 27.