ST. LOUIS – A unit that’s been a proven strength for the St. Louis Blues in recent years could lead to some complicated decisions in the near future.

The Blues defense has fallen upon tough times this season. St. Louis has allowed five-plus goals in more than a third of its games this season, and the team’s minus-30 goal differential is eighth-worst in the league this season. By those marks, the Blues are on pace for their worst defensive season since the 2007-08 campaign.

More-advanced metrics via MoneyPuck.com suggest the Blues defense is the primary culprit behind the struggles. All but one defenseman currently rostered at the top level have a larger “expected goals against” rating than an “expected goals for” rating. For the three team’s highest-paid defensemen (Justin Faulk, Colton Parayko and Torey Krug), their expected goals against totals are projected to finish worse than last season’s totals.

Solving these struggles won’t be easy, and some upcoming situations will prove telling of how the Blues navigate through it all. St. Louis’ defensive core gets a little more cluttered as Marco Scandella and Scott Perunovich return from months-long injuries. Scandella could enter the lineup as soon as Tuesday, while Perunovich has been assigned to AHL-Springfield in the short-term.

The timing of both returns is intriguing when considering the NHL trade deadline is just 10 days away. The Blues have already been active on the trade front, moving longtime star Vladimir Tarasenko and Ryan O’Reilly for many draft picks.

Moving a defenseman or trying to remodel the Blues defense at the deadline could be trickier. After packaging Niko Mikkola with Tarasenko, St. Louis does not have any other pending free agents with vast NHL experience to move. In fact, trading any of the regulars on defense would likely be difficult because many Blues blueliners hold no-trade or limited-trade clauses in their contracts.

A look at some of those situations…

• Jusitn Faulk is signed through 2026-27 at an average annual value at $6.5 million. He has a full no-trade clause through 2024-25.
• Colton Parayko is signed through 2029-30 at an average annual value at $6.5 million. He has a full no-trade clause through 2028-29 and a 15-team no-trade list for the remainder of his deal.
• Torey Krug is signed through 2026-27 at an average annual value at $6.5 million. He has a full no-trade clause through 2023-24 and a 15-team no-trade list for the remainder of his deal.
• Nick Leddy is signed through 2025-26 at an average annual value at $4 million. He has a full no-trade clause through 2024-25 and a 16-team no-trade list for the remainder of his deal.
• Marco Scandella is signed through 2023-24 at an average annual value of $3.275 million. He has a no-trade list for eight teams for the remainder of his deal.

The Blues entered the 2022-23 season with the league’s fourth highest-payroll for defenseman, almost $30 million. While it shows commitment to many guys with experience, the results simply have not lived up to the investments from this season. Only being able to dress six or seven defensemen in action regularly, the Blues could be struck with this contract conundrum for awhile.

St. Louis seems eager to explore the trade market more following the departures of established veterans Tarasenko and O’Reilly. It won’t be easy to remodel the defense, if a priority for the team, but perhaps there could be a suitor. TSN hockey insider Darren Dreger reports that it’s “very possible” the Blue move a defenseman and that Parayko has drawn some interest among contenders.

As recently as Tuesday, Parayko has been linked as a possible target for the Ottawa Senators, days after the delivered a crushing 7-2 loss to the Blues. Frank Seravelli of Daily Faceoff reports of the new interest in Parayko, plus the possibility the Blues might make a surprise move. Acquiring two first-rounders in the trades for Tarasenko and O’Reilly might allow the Blues to exchange for a defenseman with a more favorable contract, like Arizona’s Jakob Chychrun, or a forward nearing their prime, like San Jose’s Timo Meier.

Blues general manager Doug Armstrong has not made his intentions known for the upcoming trade deadline or future of the Blues defense, but he did note that after trading O’Reilly, the Blues might be interested in acquiring younger players with experience around 26 years old or younger. Chychrun or Meier could fit that bill, but likely not without some sort of change to the Blues defense.

One other consideration, the Blues take pride in defenseman playing on sides where they carry more abilities. Krug, Leddy, and Scandella are all almost exclusively left-side defensemen, while Faulk and Parayko are generally right-side players.

Calle Rosen, Tyler Tucker, and Robert Bortuzzo, all of whom have been rotating in and out throughout the season, could see their roles grow if the Blues transform their defense at the trade deadline. Scott Perunovich, once touted among the team’s top prospects, might be pushing for another chance in St. Louis post-deadline.