The frustration in Alex Pietrangelo’s voice was evident. Forget about the Norris Trophy talk or even the playoffs. In a recent conversation, the Blues’ young defenseman would have settled for keeping the puck out of the team’s net, particularly on his watch.

“I’m the guy that plays the most on the team,” Pietrangelo said two weeks ago. “I’ve got to find a way to play more consistent and play at the level I’m capable of every shift and every night, and hopefully that’s going to kick-start the team and put us in the right direction … that starts with me.”

After combining for 94 points and a plus-34 rating the past two seasons, Pietrangelo has found 2012-13 to be a steeper learning curve than anticipated. While his points are close to what he’s posted previously, the defenseman’s plus-minus rating had dropped to minus-6 during a recent three-game losing streak.

Pietrangelo, 23, had demonstrated the promise of being a leader on the back end, but it could be argued that the Blues placed him, along with fellow blueliner Kevin Shattenkirk, 24, in a position to fail. Unproven Ian Cole, unknown commodity Wade Redden and overslotted Barret Jackman split time as Pietrangelo’s partner this season, and whoever wasn’t working out with him was forced on Shattenkirk.

“It seemed like we didn’t have the combinations right, or whatever,” Shattenkirk said. “It was a lot of moving around and switching partners.”

The Blues have since taken major steps to rectify the situation, switching in new defensive partners. The trade acquisitions of Jay Bouwmeester and Jordan Leopold, pairing them with Pietrangelo and Shattenkirk, respectively, have had a calming influence inside the team’s own zone.

The Blues play in Minnesota tonight riding a season-high five-game winning streak and back-to-back 1-0 shutouts over Nashville and Detroit. They are 5-0 since Leopold, 32, joined the lineup and 4-0 since Bouwmeester, 29, came aboard.

Describing the additions recently, Blues coach Ken Hitchcock said, “Solid, responsible, smart, patient. Smart and patient would be the key, and that allows us to be better in our own zone. We’re covering over the responsible scoring areas. We recover better into those areas. Their efficient play has allowed us to get better.

“(Bouwmeester) gets a lot of the name recognition, but Leopold has added a ton to us. We had a tendency to shovel the puck and make it someone else’s problem under pressure. We don’t do that any more. We move the puck and we move our feet. We do the right things under pressure.”