Northampton director of rugby Jim Mallinder insists George North was “fit to play on” despite appearing to have been knocked out during the defeat to Leicester on Saturday.

North has a history of concussion, having suffered four head blows in five months between November 2014 and March 2015, including two in one game against England in the Six Nations.

Following his final concussion, North spent five months on the sidelines as World Rugby changed their Head Injury Assessment protocols as a result.

However, players’ safety came overshadowed Saints’ 19-11 defeat at Welford Road, when North was tackled in the air and landed on his neck, with his assailant Adam Thompstone being consequently sin-binned.

North was assessed by the club doctor before being declared okay to continue and Mallinder backed the assessment, insisting the Wales winger was not knocked unconscious, despite the broadcast pictures.

"I don't make those decisions and our doctors and medical staff are really clear that if anyone gets knocked unconscious or has had a knock where they look like they are unconscious, they need to come straight off," Mallinder said.

"It's as simple as that. You don't go to be assessed - you are off straight away. George has had some previous issues so he took it steady.

"The doctor was very, very happy even as he walked off that he was just going to go for an assessment and thankfully he could come back on."

A club statement added: "George was communicating immediately with attending medics and complaining of neck pain.

"Significant neck injury was excluded on the field but on review of video footage pitch side, the team followed World Rugby protocols and used a Head Injury Assessment given the potential mechanism for head injury.

"George was fully assessed by the doctor and passed fit to return to play."

North assured fans he was well after the defeat and thanked the club doctors for their support, although admitted he was worried about the injury to his neck.

"Thanks for all the messages. I am OK," North said on Twitter.