UEFA will ask FIFA and football's lawmakers to review their concussion guidelines to ease the pressure on doctors and ensure that concussed players are not allowed to continue playing, the organisation said on Wednesday following a series of worrying incidents.

European football's governing body want The International Football Association Board (IFAB), who manage the laws of the game, to "consider potential changes to the Laws of the Game (such as in terms of substitutions)" to allow the sport to move forward in handling concussion in a more responsible way.

At present, referees must stop the match to allow the injured player to be assessed by the team doctor. The player can only continue with specific confirmation by the team doctor to the referee that he is fit to do so.

However, the world players' union FIFPRo said this does not go far enough. They want temporary substitutions to be allowed while a player is examined and authorisation given by a neutral, rather than a team doctor.

"I strongly believe that the current regulations on concussion need updating to protect both the players and the doctors and to ensure appropriate diagnosis can be made without disadvantaging the teams affected," UEFA president Aleksander Ceferin said.

During Tottenham's Champions League semifinal first leg clash with Ajax, Jan Vertonghen suffered a head injury and initially returned to the pitch, before was forced to go off moments later and appeared to collapse on the sidelines.