The 17-year-old was a 63rd-minute substitute in Portsmouth's 2-2 Championship draw on Saturday against Middlesbrough, who had Ryan's older brother, Rhys, in their side.

Cotterill said giving the teenager his debut was exciting for him as he could see the Perth-born midfielder having a fruitful career.

“I'm delighted we've been able to get young Ryan Williams on the pitch,” Cotterill told BBC Sport. “I've got a thing about him. He's a player for 17. He'll get better, he's a great kid.

“I love his attitude, he's got a bit of fire in his belly. It was fantastic seeing him on the pitch today.”

Financially-troubled Portsmouth, who have a small squad, only elevated Williams to the first-team last week.

However Cotterill said the ECU Joondalup junior, who turns 18 in late October, deserved his place and made an impact against Boro.

“I think that'll be my memory when I look back at this game, getting him on the pitch,” Cotterill said.

“I really wanted to do it. I didn't do it because I like him or because he's 17. I put him on because I thought he might make something happen for us.”

He added: “But the subs came on and played their part. Without them we wouldn’t have got the result we did.”