Wolves striker Raul Jimenez is conscious and responding to treatment after he was stretchered off following a clash of heads with Arsenal defender David Luiz during Sunday's game at the Emirates Stadium.
Jimenez was given oxygen after the accidental coming together and was eventually replaced by Fabio Silva.
The clash of heads occurred early in the match and resulted in a lengthy delay of around 10 minutes as paramedics and medical staff saw to both players. There is cautious optimism surrounding Jimenez's condition.
Luiz carried on, however, albeit with a bandaged head, with the score 0-0 at the time of the incident.
He went to check on Jimenez before he returned to the pitch but was withdrawn at half-time with Rob Holding his replacement.
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The Brazilian, who passed on his best wishes to Jimenez, received seven stitches in a three-inch wound, close to his hairline.
Brain injury association charity Headway released a statement on Monday expressing its "anger and disappointment at football's continued failings to protect its players from concussion" and reiterated its view that temporary concussion substitutes are "urgently" needed.
Something is not right. This cannot be allowed to continue. How many warnings does football need?
Headway questioned whether Luiz would have been cleared to continue if concussion substitutes were in place.
Luke Griggs, deputy chief executive at Headway, said: "Too often in football, we see players returning to the pitch having undergone a concussion assessment - only to be withdrawn a few minutes later when it is clear that they are not fit to continue.
"That is the very reason why we urgently need temporary concussion substitutes in football. You simply cannot take a risk with head injuries. They are not like muscular injuries where you can put a player back on 'to see if they can it if off'. One further blow to the head when concussed could have serious consequences.
"The question that has to be asked is had the concussion substitutes rule been in place, would Luiz have been allowed to return to the field of play? Would that extra time in the treatment room have led to a different decision being made?
"The concussion protocol clearly states that 'anyone with a suspected concussion must be immediately removed from play', while the sport continues to promote an 'if in doubt, sit it out' approach to head injuries.
"Time and time again we are seeing this rhetoric not being borne out by actions on the pitch. Something is not right. This cannot be allowed to continue. How many warnings does football need?"
Headway also offered their support to Jimenez on social media, writing: "All our thoughts are with Raul Jimenez, his family and team-mates right now.
"No doubt there will be lots more talk about concussion subs in football, but right now let's just focus our thoughts on Raul."
Coady: Jimenez awake and breathing
Wolves captain Conor Coady said the thoughts of everyone on the pitch were with Jimenez and Luiz after their horrific clash of heads.
Coady went up for the header immediately behind Jimenez and Luiz and admitted both sides were shaken by the collision.
"It was something you knew straight away - we hope David Luiz is OK as well - it was a horrible clash of heads," Coady said.
"This happens in football but you don't like to see it and I think both sets of teams went out and then played properly.
"It was a tough thing that happened. He is with the right people and that's the most important thing but we just hope and pray that everything is OK because he is the one we are thinking about right now.
"I was at the front just behind him, so I jumped with them as well and you hear it and, as they dropped, he was on his side. It's something we never want to see.
"He is in the hospital and by all accounts he is awake and breathing. The first question we asked when we went in was 'how is Raul?' It's important now we remember the game but most importantly we get Raul sorted."
Nuno: Jimenez will have scan but is alert
Nuno Espirito Santo also appeared cautiously optimistic that Jimenez's condition was improving, adding he is in the hands of medical experts and will undergo tests.
The Wolves head coach also expressed pride at the way his side were able to absorb the effects of witnessing their team-mate be stretchered off and put in a winning performance.
"He is doing a scan now but he is conscious, he is OK inside the gravity of the problem of course," Nuno said.
"By the reaction of the team-mates, of everybody, you start hearing code red. When they say it is red it is because it is serious. It was a bad moment for everybody.
"Both teams and both players, players of Arsenal are worrying about him and we wish everything to be OK.
"He speaks, he is aware, but now we have to have a proper assessment but he is in good hands.
"I am very proud today, I always am but especially today because this team showed heart, a will, a belief. It was really good to see."
Trials of additional permanent concussion substitutes could begin in January, the game's law-makers have announced.
The International Football Association Board (IFAB) said its Concussion Expert Group (CEG) had met on Wednesday and said it was now preparing the ground for competitions to test new protocols.
"The members (of the expert group) recommended further consultation, working with the FIFA medical subdivision and other stakeholders, to facilitate trials to start from January 2021 for any competition that is interested in taking part," a statement on the IFAB website read.
The statement also said: "The CEG again emphasised that the protection of players is the main goal and that a clear and uniform approach is needed, which can operate effectively at all levels of the game.
"Therefore, the group agreed that applying an 'if in doubt, take them out' philosophy would be the best solution to safeguard the health of football players."