The defender was allowed play on after a horror head injury

Tottenham Hotspur manager Mauricio Pochettino has backed his club's medical team, after defender Jan Vertonghen was temporarily allowed to play on after suffering a head injury.

The Belgian centre-back was left bloodied after a clash of heads with teammate Toby Alderweireld, during the first half of their 1-0 Champions League semi-final first leg defeat in North London.

After receiving treatment, Vertonghen continued to play on, before being helped from the pitch in visible distress.

The club have been heavily criticised overnight for allowing Vertonghen to continue on playing, despite needing five minutes of treatment on the pitch. Manager Mauricio Pochettino says he has no regrets over how his staff handled the situation.

"Of course I was worried, it's normal," he said.

"For me the most important thing is the health of the player.

"In that moment the doctor decides it's OK. The medical staff are the boss on the decision.

"I wasn't involved. It was the doctor's decision,

"The rules and the protocols are there. Our medical staff followed the protocol.

"He's OK. We hope it is not a big issue. He walked away from the stadium. We know we have to keep watching and monitoring him because it was a big knock," he added.

Ajax won the first leg 1-0, courtesy of Donny van de Beek's first half goal, leaving them on the verge of a place in the Champions League final for the first time in 23 years.

Spurs will welcome forward Son Heung-Min back for the second leg in Amsterdam next week, but history isn't on their side. In 17 previous occasions when a home side have lost their semi-final first leg in the last four of the semi-finals, only one team has overturned the deficit.

Pochettino is remaining positive though: "It's about preparing for the second leg. We will try to win. It will be tough for us, but also tough for them."