Souness was unimpressed by Lewis-Skelly mocking Erling Haaland's goal celebration after his strike in victory over Manchester City last week.
He wrote in the Daily Mail: "I like Arsenal’s Myles Lewis-Skelly. Attitude is oozing out of him and it’s why I think he’s going to be a real player.
"He put in a strong performance during Arsenal’s 5-1 defeat of Manchester City last weekend which included him mimicking Erling Haaland’s goal celebration after extending his team’s lead.
"I love attitude in all walks of life – and not just in the football world. People who go out there and say: ‘This is me. I’m going to do this.’ I like to see players who have b******s, too.
"But I have to say, having seen that celebration, I think he needs to wind his neck in.
"At 18, it’s a bit early to be going down the road of mimicking a player like Haaland, someone who’s achieved great things in our league.
"Wait till you’ve won a few things in our game, son. Just give it a few years. Listen and learn every day until then. Know that someone so young going down that road is not a good look."