Liverpool boss Jurgen Klopp says the introduction of concussion substitutes "makes sense" after David Luiz played on with blood seeping from his head bandage as Arsenal lost to Wolves, reports BBC Sport.
The defender clashed heads with Wolves striker Raul Jimenez, who has since had surgery on a fractured skull.
Arsenal said protocols were followed regarding the decision to allow Luiz to play on after Sunday's incident.
Asked at a news conference whether he would be in favour of concussion substitutes, Klopp said: "At that moment I didn't think about a rule change, I was just sitting there for 10 minutes hoping that they would both get up without any issues, but that didn't happen.
"I know we have concussion protocols and I'm pretty sure Arsenal did that. I'm not sure any rule would help in that moment because the player can play on.
"But, yes, it makes sense that we can do things like this, of course."