Newcastle striker Aleksandar Mitrovic has apologised to the club's doctor after having to be restrained as he tried to return to the pitch following a head injury.
The 21-year-old Serbia international was knocked unconscious minutes after scoring the Magpies' equaliser in Sunday's 1-1 derby draw with Sunderland at St James' Park.
However, having come around and being led to the sidelines, he was desperate to return as his side pressed for a last-gasp winner, and had to be physically restrained by doctor Paul Catterson as he followed Barclays Premier League protocol, as well as manager Rafael Benitez.
Mitrovic told Serbian newspaper Blic: "I didn't know what the procedure was. I didn't know the rules.
"I apologised to the doctor after the game because I knew I had to come off after being knocked unconscious for a few seconds. I've been through the examinations, my head is fine."
Mitrovic had earlier snatched a point for the Magpies with a towering header, his sixth goal of the season, prompting Benitez to suggest he could be the man to fire the club out of relegation trouble if he gets the right service and support.