A head injury for Jan Vertonghen marred the opening 45 minutes of Tottenham Hotspurs' Champions League clash with Ajax this evening, leaving "a lot of questions" to be answered, according to RTÉ football pundit Richie Sadlier.
The centre-half left the field to be treated for a blood injury after colliding in the air with teammate Toby Alderweirald, but once he returned to the fold it became clear he was far from fit for action.
After signalling to the sideline to come off, the Belgian international walked off the pitched before having to be physically held up by medical staff.
It wasn't a good look for either Mauricio Pochettino or his backroom team as the referee had appeared to be engaged in a conversation with them regarding the player's health, and a possible concussion, before the defender returned to the game.
On Virgin Media's half-time coverage, Niall Quinn also addressed the incident, claiming the sport needs to act regarding the issue of head injuries
It's almost like he's semi-feinting there; something has obviously happened as he has run back onto the pitch. It's obviously looking really bad for the decision that was taken to put him back on.
Rugby dealt with this a long time ago; football needs to deal with it now. The blood-sub [needs] to come on. The did it in GAA here as well. You just cannot take any chances. Give it ten minutes and see how things go.
There have been calls made for introducing independent doctors for situations such as tonight's in the past, with similar arguments set to intensify over the coming days.
Concussion, coincidentally, was an topic covered during Virgin Media's pre-match discussion, with Quinn making the link between heading the ball and dementia later in life.
"It's more than a passing concern now.
"A lot of my friends have dementia creeping in and it does point to heading the ball."
Niall Quinn on the links between football and dementia following the deaths of #CelticFC legends Billy McNeill & Stevie Chalmers.#VMSport pic.twitter.com/sqIq0y7ZAp
— Virgin Media Sport (@VMSportIE) April 30, 2019
Ajax currently hold a 1-0 lead in the tie, after Donny van de Beek put the visitors ahead in the 15th minute.
— RTÉ Soccer (@RTEsoccer) April 30, 2019
The Dutch side have dominated the first half, in terms of possession, though the home side have had their chances in front of goal, since the start of the second half.
Vertonghen's injury, however, has forced Pochettino into somewhat of a tactical rejig with midfielder Moussa Sissoko coming on in his place.