Former Arsenal defender Martin Keown has urged Kieran Tierney not to shy away from kicking teammates in training.

Keown was reacting to reports that Tierney's team-mates have been complaining about his hard challenges during training.

"I'm told the players told him to calm down a little bit," Keown told Stadium Astro.

"I think I'd have been saying, 'this is how I train'. Everyone knew that [with me]. I wore screw-in boots in training.

"Thierry Henry used to go berserk because he thought I was trying to kick him in training every day. But I just couldn't wear moulded boots, I had to wear screw-in boots.

"I wanted to be at my best, and I think Tierney's the same.

"He shouldn't apologise for it. In fact, that should be the level of training.

"As it was back then. I can tell you on the training pitch it was white hot, it was very competitive."