Arsenal boss Arteta backs temporary subs for head injuries

Luiz played on until half-time of Sunday's match, with Arsenal insisting concussion protocols were followed, but was replaced as blood continued to seep through his head bandage.

He has been ruled out of Thursday's Europa League match against Rapid Vienna but could be fit for Sunday's north London derby at Tottenham.

"Maybe it is a moment that we can think to give these people a little bit more time and use a temporary substitution, for example, if we don't want to find ourselves in those positions," Arteta told reporters ahead of the Rapid match.

Arsenal faced fierce criticism for not replacing the Brazilian defender immediately after the collision, which occurred just five minutes into the Premier League match with Wolves at the Emirates.

But Arteta said that Arsenal's club doctor Gary O'Driscoll had followed the rules.

"He knows exactly what to do," said the Spaniard. "He did all the testing, he followed all the protocols and we were very comfortable for him (Luiz) to carry on playing.

"But obviously you have to make a decision in one minute, when somebody is bleeding, when you have someone with a massive concussion next to you -- whose life is under threat."

Arteta said it was impossible to avoid accidental clashes in football and that sometimes they would lead to serious injuries.

"Obviously, it's never happened in football," he added, referring to concussion substitutes. "It happens and it's very common in other sports.

"And it's just a suggestion. You know I want to be extra protective, which I think we have to be in certain moments when we really are considering the welfare of the players and have a fair competition while the game is still running."