An unshakable self-belief.

That’s what former professional English league goalkeeper Paul Barron feels drove Kasey Keller to succeed in a world full of stellar netminders.

It all began for Keller — a four-time World Cup participant — at the Northwest Soccer Camp, which recently kicked off its seven-week run at Bastyr University in Kenmore. The camp, run by United States Soccer Hall of Famer Cliff McCrath, is in its 41st year.

“He was an absolute pain in the backside. There weren’t enough hours in the day,” Barron laughed on Monday about Keller’s work ethic as a youngster. Barron has coached at Northwest for 33 years and took Keller under his wing from ages 9-18.

Keller smiled and agreed with his mentor’s assessment of a young, self-described “arrogant” goalkeeper from Lacey: “I tried everything I could to sneak into the older group, every chance I had. Eventually, it was, ‘OK, you’ve got to put me in the older group,’ because, hopefully, I was beating a lot of the older guys. But that’s what I wanted to do, even at 10 or 11, I didn’t want to be with those kids — I wanted to be challenging myself.”

The former Seattle Sounders star and first American goalkeeper to become a regular in the German Bundesliga, the English Premier League and the Spanish La Liga has returned to the Northwest camp to coach for four days.

And the memories continued to flow freely for Keller, 42, about his mindset back when he was at camp, following Monday’s afternoon session.

“When I got to be 16-17 and Paul was explaining about us training together at camp, I was trying to beat him. I was trying to show every parent, every kid that I was trying to be better than the pro who was playing in England at the time, because that’s what my goal was,” Keller said.

“Paul was a big influence on myself. As an American kid, there was no MLS at the time and you didn’t have any pro goalkeepers to look up to. Paul became that kind of mentor early on in my development — which kind of worked out OK,” he added with a booming laugh.

Barron, 58, stressed that Keller went through some rigorous training back then, but mental and physical strength and a good support system of family and friends pushed him along the way.

“Push it wide, out of the danger area … Get those hands up … Hold that corner… well done,” were some of the messages Keller and Barron sent campers’ ways during their two-hour session.

When one goalie hesitated to challenge a shooter for a rebound, Barron encouraged him to go for the ball even if a slight collision might occur.

“Don’t worry about your looks, son,” Barron said with a smile.

“That’s right, you’re a goalkeeper,” Keller added.

Teen goalkeepers Katie McGuire, Ashley Swan and Oliver Wisseman said that it was a great experience training and interacting with Keller and Barron during Monday’s session. Swan said her diving ability is sure to improve after watching Keller make a plethora of saves.

“I think it’s nice having Kasey there because he is able to not only tell us what to do, but also show it,” McGuire said. “When you’re with a professional player, (you say), ‘OK, gotta do it that way.'”

Added Wisseman: “(Keller) definitely made me want to push harder and try to do my best and really absorb everything he had to tell me.”

Barron, who has trained Australian World Cup star Mark Schwarzer among many others, liked what he saw on the field with his crop of goalkeepers at Bastyr.

“This lot, as a group, are excellent. The attitudes are fantastic, the work ethic is really really good, so it’s been a pleasure to work with them,” he  said.

Keller, who retired last season after a 22-year career, has been spending his time on the Sounders’ broadcast team and has worked some Euro Cup 2012 games, as well.

Returning to the camp and coaching alongside the mentor that molded him into a star goalkeeper was a no-brainer.

“Northwest Soccer Camp was a big part of my development, to the point where Cliff married me and my wife. So there’s a lot of history there and it’s nice to be able to give some of that back,” he said.

Camp Executive Director Denise Foreman noted that all the goalkeepers at the camp get some one-on-one time on the field with Keller during his stay.

“I’ve always said that if I’m going to put my name on something, I’m not just going to show up and sign a few autographs. I’m going to interact and be part of the process, and the kids are going to go home and say, ‘You know, Kasey’s kind of my friend, as well,'” Keller said.

Added McCrath, 76, about having Keller back on board: “It’s unbelievable, and it’s like having a great dream, waking up and getting back to reality and then realizing, ‘Wait a minute, the dream is reality.’ Here’s probably the best goalkeeper the U.S. has ever had. He’s really the real deal.”

For information, visit www.nwsoccer.org