Tottenham Hotspur manager Mauricio Pochettino will back potential changes to the concussion protocols after defender Jan Vertonghen suffered a serious head injury against Ajax Amsterdam.
Vertonghen collided with team mate Toby Alderweireld while trying to beat Ajax goalkeeper Andre Onana to the ball during Tuesday's Champions League semi-final first leg.
After speaking to the Spurs medical staff, Referee Antonio Mateu Lahoz allowed Vertonghen to return to the pitch, before what appeared to be a delayed concussion forced the 32-year-old to go off again.
Pochettino defended the club's medical staff, saying player welfare remains a top priority for the club.
"Always in that situation I am open, more than open, to improve the decisions. I think the most important thing was going to be the health of the player," the Argentine manager told a news conference on Thursday.
British brain injury charity Headway has since urged the football authorities to introduce temporary substitutions to allow medical staff more time to conduct off-pitch assessments.
"It is not important, the game, the semi-final of the Champions League, the score, the priority is the player," Pochettino added.
"I don't know if we need to change the rules, if we need another doctor."
FIFA is open to having discussions about temporary substitutions if players suffer head injuries, according to medical committee head Michel D'Hooghe.
Vertonghen saw a neurologist on Thursday and Pochettino is still unsure whether the centre back will be available for Saturday's Premier League clash against Bournemouth.
"We still haven't received the report, but after the game he was good. I think he was more relaxed and he felt better. But we need to receive the report from the specialist," Pochettino said.
Lionel Messi's devastating double put Barcelona on the verge of the Champions League final after a 3-0 home win over Liverpool on Wednesday.
Inspired by Messi's heroics at the Nou Camp, Pochettino said Spurs will need to match the Barcelona forward's desire on the pitch if they to overturn a 1-0 deficit in Amsterdam on Wednesday and reach their first-ever Champions League final.
"It's so painful when in the same semi-final you watch Messi play with the desire and motivation, and say 'why did we not feel the same?'," Pochettino said.
"If we play like him without the ball, with the desire he showed yesterday, for sure we are going to have the chance to qualify for the final. If not, no chance."