Tottenham handed Lucas Bergvall injury blow as concussion substitute rules explained

Lucas Bergvall is poised for a spell on the side-lines after he suffered a suspected concussion during Tottenham Hotspur's clash against rivals Chelsea.

Bergvall, 19, was deployed by Thomas Frankto face the west Londoners. However, his evening came to an end after only seven minutes when he was hit in the side of the head by a volleyed clearance from Enzo Fernandez.

He struggled to run in a straight line from that moment on and, after a brief, pitch-side consultation with Spurs' medical team, he was told he must leave the pitch. The young Swede was heartbroken and frustrated as he was desperate to carry on.

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When he was informed he wouldn't be returning to the pitch, the teenager promptly stormed down the tunnel. Bergvall was replaced by Xavi Simons, who was close to signing for the Blues this summer before the Lilywhites swayed him to north London, came on as a concussion substitution.

Owing to Bergvall specifically being forced to leave the pitch because of a suspected concussion, there are strict rules in place as to when he can return to training and in turn games. In 2021, the Premier League overhauled their rules regarding concussed players.

In a bid to bring their approach in line for the International Football Association Board (IFAB), it was decided that teams should be allowed to replace concussed players, without it counting as one of their five substitutions.

The intention behind this alteration was to ensure teams don't find themselves numerically disadvantaged due to a concussion. Raul Jimenez's head injury against Arsenal, when he was at Wolves, which saw him miss several months of football, prompted the rule changes.

Any incident is assessed by an independent tunnel doctor, who investigates the footage of the matter. While this process is ongoing, a team can then apply for the concussion substitute to be applied.

If it's decided a player has suffered a concussion, or a brain injury, they cannot be allowed to return to the pitch. When there are no immediate symptoms of a concussion, they will remain in a space for a continually observed period whereby medical staff monitor the wellbeing of each player.

Moreover, at half-time or full-time, there will be a formal clinical assessment of the player with the head injury to ensure no clear symptoms have developed into anything more serious.

When detailing what must happen to a player after the match, the Premier League website states: "As well as any formal clinical assessment of the replaced player, his recovery will be audited by the relevant medical staff to ensure that The FA's concussion guidelines for an advanced care setting are followed for his return to action.

"If the formal post-match medical assessment reveals no concussive injury, then the player is cleared to return to training as directed by the club's medical team.

"Any club who have carried out an APCS must submit to the Premier League, medical information on the player as well as a report of the APCS procedures within seven days of that player returning to training or playing."