Players never want to come off.
They're warriors, they take knocks all the time, they don't want to be pulled from the battlefield when their team mates are still fighting.
Awareness and treatment of head injuries in rugby is increasing but there's still some way to go.
Too many times players are trying to rail against coming off and if they think they can get away with it, they will. Head injuries is a tough one for someone to come to terms with too. You can't see it, no-one else can see it and something as simple as the optics of walking off can be enough to make a tough man think it's not a sufficient enough reason to withdraw.
On Saturday, during Leinster's Champions Cup clash in Glasgow, Ryan Wilson went off twice with a head injury.
He came off.
https://twitter.com/GlasgowWarriors/status/921710832333017088
Then he came back on.
https://twitter.com/GlasgowWarriors/status/921714536171831296
Then he came back off.
https://twitter.com/GlasgowWarriors/status/921715787404111872
Four minutes was the difference between Wilson returning to the field and then returning to the changing room despite his protestations that he didn't want to go off.
Thankfully, the referee intervened and took the decision out of his hands after the player looked very uneasy on his feet.
https://twitter.com/peterrobinson86/status/921716497604542464
https://twitter.com/therugbycoach1/status/921716883606441984
https://twitter.com/MJW1876/status/921716990770900992
The Glasgow captain was announced in the loud speaker to have been subbed permanently before he had even left the field and then, again in the first half, another player was taken off.
Tim Swinson had to go for a HIA after taking a bang to the head and looking very unsteady himself.
https://twitter.com/ConanDoherty/status/921716860780974081
Swinson was subbed straight off for an assessment but he also looked unhappy about it as he headed for the tunnel seemingly arguing with the medics.
