At last season’s training camp, the Pittsburgh Penguins had a backlog of defensemen vying for a position on the NHL roster. But with six veteran blueliners locked into spots there was little room for the team’s talented plethora of defensive prospects to crack the lineup.

That however didn’t stop 19-year-old stud Olli Maatta from making the jump.

But entering this upcoming September training camp there are more openings for prospects to earn a spot on the Penguins’ roster.

With the offseason departures of Brooks Orpik, Matt Niskanen and Deryk Engelland and shoulder surgeries for Maatta and fellow 2012 first-round pick Derrick Pouliot, there are multiple positions needing filled on the Penguins’ back end for the start of camp, and maybe the start of the regular season.

“We want to bring young players into our organization, especially on defense,” associate general manager Jason Botterill said. “We’ve talked about these young defensemen in our system for a while and it’s time for Brian Dumoulin, Scott Harrington, Simon Despres, to get an opportunity.”

Despres is a certainly a candidate to take a spot. The two other possibilities Botterill mentioned – Harrington and Dumoulin – are currently attending the Penguins development camp. And they are aware of their opportunities this fall.

“There are some openings, but they’re not just going to give it to me,” Dumoulin said. “There are a lot of good, quality D here. It’s going to be a challenge. We’re all going to be pushing each other for those spots. It’s going to be a challenge, but it’s going to be fun.”

Dumoulin, 22, has played the past two seasons with Wilkes-Barre/Scranton of the American Hockey League. He also made his NHL debut last year, appearing in six games for Pittsburgh.

The Boston College alum and two-time NCAA national champion has great size (6-foot-4, 219 pounds) and has fine-tuned his game since making the transition from college hockey to the professional ranks.

“I got tougher to play against in the D zone. Not necessarily big hits, but making plays in the corner,” Dumoulin said. “(WBS head) coach (John) Hynes has really pushed me in that aspect.”

Dumoulin also became more active joining the rush, something new Penguins head coach Mike Johnston wants to emphasize this upcoming season.

“Toward the end of the season this year I got involved in the offense,” Dumoulin said. “I know that’s one thing that coach Johnston is really stressing. It was good for me to improve on that last year.”

Harrington, 21, had a storied career with the London Knights of the Ontario Hockey League. He twice led his club to the OHL championship, once as captain and once as alternate captain, while twice being named OHL First-Team All-Star.

The Penguins’ second-round pick (54th overall) in the 2011 NHL Draft completed his first year of pro hockey last year with WBS. Harrington learned a lot from his coaches during last season and he hopes that shows during this week’s development camp and in training camp.

“I just want to show them that I’ve picked up the pointers and recommendations that they’ve given me over the year in Wilkes-Barre,” Harrington said. “All the stuff that we worked on is second nature. I’ve grown as a player.

“I learned a lot and really enjoyed my year. I think I had a good year and made a lot of progress. I’m here to show that this week to the new coaches who haven’t seen me so far.”

Even though the upcoming training camp may be their best shot ever to make Pittsburgh’s roster, Harrington and Dumoulin, both of whom helped lead WBS into the AHL conference finals last season, aren’t looking that far ahead.

“It’s causing me to push myself even harder this summer knowing that there’s an opportunity for me,” Dumoulin said. “They’re not going to just give it to me. I have to earn it. It’s what I do from now until training camp is what will determine whether I have a better or lesser opportunity.”

Harrington echoed that sentiment.

“You approach every camp with the same mentality no matter who’s in front of you. You want to make the team,” Harrington said. “You could get caught up in that stuff. It could effect the way you think and the way you train. There’s still a couple weeks left in the summer after this camp. I think it’ll just be important for myself and the other defensemen to prepare ourselves the best we can because this development camp and upcoming main camp are important for us.

“I want to show (the coaches) that I’m ready to hopefully make that next step and get an opportunity to do that.”