That offensive game, however, is one he reined in to be the player his coaches wanted him to be throughout the season with the United States National Team Development Program.
NHL Central Scouting's Gary Eggleston said Wrenn "plays a smart and steady game. He skates very well and has good mobility. He passes the puck quickly out of his own end. He backs up the play and his partner very well, and is a reliable stay-at-home defenseman. He plays the body very well and is a physical presence. He works very hard game in and game out and is consistent in his overall play. He is smart and poised and doesn't get rattled when pressured."
"My strong point is playing hard, tough defense," Wrenn said. "I like to hit and be physical, get in kids' faces. I'm good making the first pass to get out of our zone and I'm well-positioned.
"This was my first year at NTDP, and my offensive production fell off. The coaches on my team wanted me to be the best defensive defenseman I can be and told me to let other people worry about providing offense.
"The Under-18s showed that I do have offensive ability. I got confidence and showed I have some versatility, some offensive skills."
Wrenn had just 6 goals and 17 points in 60 games with the national team, but at the World Under-18's, he had 3 goals -- all on the power play -- in seven games. He also was a plus-5 with no penalties as he captained the team to a 5-0 shutout of Russia in the gold-medal game.
"I had won a national peewee championship with the L.A. Selects, but winning the World Under-18s was definitely the biggest accomplishment in my career," Wrenn said. "We worked two years for that gold medal and it actually happened. The crowd was chanting, 'USA, USA.' Going up to get that trophy and then bringing it back to my teammates was the best feeling I have ever had."
"This was my first year at NTDP, and my offensive production fell off. The coaches on my team wanted me to be the best defensive defenseman I can be and told me to let other people worry about providing offense. The Under-18s showed that I do have offensive ability. I got confidence and showed I have some versatility, some offensive skills."
-- William Wrenn
Wrenn started playing hockey for the same Anchorage Boys and Girls Club program that has provided the NHL with Scott Gomez.
"I was young and looking for things to try, and hockey is pretty big in Alaska," Wrenn said. "My friends were trying out so I went to public skating at the mall rink and enjoyed it. I got a whole bunch of used gear and went to clinics. At first I thought it wasn't for me, but my parents said keep trying and see what happens. I started to like it and then fell in love with it.
"I was average until my first year of competitive hockey, which was two or three years after I started. Then I played for the Alaska All-Stars, where I did a lot of hard work and got great coaching from Bill Cohen, who showed a lot of faith in me. I was with them until bantam AAA.
"Then I played two years with the Los Angeles Selects, being coached by Jeff Turcotte and Newell Brown, the assistant coach of the Anaheim Ducks. We won the bantam national championship my first year and lost the next year in the semifinal."
NTDP scouts were watching.
"They scouted me at tournaments and select festivals," Wrenn said. "They talked to me at the summer festival after my bantam AAA year and offered me a spot. I spent two years with the development program and coach Ron Rolston. I learned a lot about defensive body positioning, stick positioning, not being too aggressive, and learning that keeping it simple is right. Ron made it clear that hard work gets you everywhere and you're not going anywhere without it."
It's a bit surprising that Wrenn's hockey hero is Joe Sakic.
"I used to be a forward when I was younger," he said. "I really liked the way he played and I liked that Avalanche team with Ray Bourque, Rob Blake, Peter Forsberg and Joe Sakic, who was my favorite player and a great leader.
"I wear No. 19 because of Joe Sakic and I try to get it every year. I switched to defense in peewee AAA when my coach asked me to volunteer. I thought, why not give it a try? It all seems to have worked out now. It was a change at first. I scored a lot less goals."
Wrenn will attend the University of Denver this fall, along with fellow Alaskan and NTDP player, goalie Adam Murray.
"It's definitely going to be nice going to Denver with Adam, since we grew up together and are best friends," Wrenn said. "It will be fun and I'll be looking forward to it. Going away to college is nothing new. I left home a couple of years ago when I moved to Los Angeles to play hockey."