The second-year defenseman is the X-factor player on this team. With Eric Brewer facing an uncertain future, the Blues could really use another puck-moving defenseman.

Could Pietrangelo become that player?

The skill is a given. He is destined to be a power-play quarterback in the NHL. He has the size, the skating ability, the puck skills and the ice vision to make that happen.

He has remained relatively healthy in the past year, allowing him to get bigger and stronger. But does he really want to stick in the NHL this season?

THAT is the issue. Andy Murray is a demanding coach. He expects Pietrangelo to work his way onto the team. He expects the youngster to demonstrate the sense of urgency lacking last year, when he was sent back to junior hockey to continue his maturation.

Pietrangelo’s skill was obvious during the team’s developmental camp this summer. But he wasn’t the hardest-working guy on the ice — in part because he was so much better than some of the hopefuls on hand.

He needs to step it up, starting this weekend as the Blues take off for Traverse City and the annual prospects tourney in Northern Michigan.

He has more to gain than anybody else on the Blues tourney roster. It is a big event for goaltender Jake Allen and center Phil McRae, but they are set for another year of junior hockey and a bid to represent their countries in the World Junior Championships this year.

Brett Sonne would like to show well to boost his stock heading into the camp for the Blues and then, in all likelihood, the Peoria Rivermen. The same goes for former University of Michigan star Aaron Palushaj.

Big defenseman Brett Ponich gets a head start on what could become a pivotal junior season in his career.

Of all the players, though, Pietrangelo holds the most immediate value to the Blues. Can he use this event to propel him toward earning a top 6 defensive role in St. Louis?

Or will he remind the hockey staff that he is not quite ready to take that step?

If he can make the group, his skill set would mix well with lead defenseman Erik Johnson, hard-hitting Roman Polak, puck mover Carlo Colaiacovo, veteran Barret Jackman and one of the following: Mike Weaver, Tyson Strachan, Brendan Bell or Jonas Junland.

Daryl Sydor got on invite to training camp, due to all his good work for former Dallas Stars GM Doug Armstrong. But this move does not excite Hockey Guy.

if Pietrangelo can’t make the group, then the comeback timetable of Eric Brewer could become more critical. Depending on what Bell showed, the Blues could need to add another offensive defenseman to bridge the gap this year.

Alex’s ascension, if it occurs, would boost the skill level of this team and balance the roster nicely.