The Tampa Bay Lightning entered play in the 2014-15 regular season with 8 NHL-capable defensmen.

Anton Stralman and Jason Garrison as offseason additions bolstered a returning group featuring Victor Hedman, Matt Carle, Radko Gudas, Eric Brewer, Andrej Sustr, and Mark Barberio.

Defensive depth, then, was a strength heading into the season. So much so, in fact, that Eric Brewer was moved for a 3rd round pick in the 2015 draft. That got the veteran out of the pressbox and onto the ice, and freed up minutes for Sustr and Barberio -- guys with a little bit more mobility -- to draw into the lineup.

While Sustr has seen more of the ice, primarily due to the fact that he's a right shot, Barberio's games played and time on ice have increased steadily as the year has progressed; he played in 2 games in October (when Victor Hedman was injured on a road trip through Western Canada), 5 games in November, and 9 games in December, totaling just one assist in all that time (almost 300 minutes of ice in all situations).

With Radko Gudas expected to miss significant time, the question becomes: what do the Lightning do on the blue line?

The best answer might already be on the roster.

Mark Barberio is a left shot, but he has plenty of experience playing the right side in the NHL. Slotting him in the top-4 might be Jon Cooper's best option at the moment.

Victor Hedman - Mark Barberio Matt Carle - Anton Stralman Jason Garrison - Andrej Sustr Nikita Nesterov

That spreads the talent around, giving Barberio a reliable partner to skate with, though it does also expose him to significantly more minutes and tougher assignments than he's used to.

There are obvious concerns. For a guy billed as a "power play specialist" and "puck-moving defenseman", Barberio's low point total might have some folks a bit worried; where's the offense been? And what has Barberio done to earn a look in the top-4 now that Radko Gudas will miss time due to arthroscopic knee surgery?

The simplest way to explain the lack of point production is with a quick look at his on-ice shooting percentage at 5v5 -- or how well the Lightning have scored at even strength with Barberio on the ice. He doesn't have a lot of control over how well his teammates shoot the puck, and in fact, just 4.96% of Lightning shots are going in the net so far this year through 261:13 of 5v5 time with Barberio on. That's last on the Lightning by quite a bit and indicative of a downturn in pure, dumb luck -- last year, the Bolts shot 8.81% at evens with Barberio on.

Because percentages can be so fickle, and goaltending and shooting vary so greatly, looking at how Barberio has affected Tampa Bay's puck possession game is a preferred assessment of him as a player. Barberio is a 54% Corsi For skater this year with a +0.5% CorsiRel, which means he is positively impacting Tampa Bay's ability to control possession of the puck when he's on the ice. He's been a positive CorsiRel player for three consecutive years with Tampa Bay dating back to the lockout-shortened 2012-13 season, albeit in a very limited and sheltered NHL role.

Still, the signs are all good -- Barberio might just be ready for more time on ice and harder assignments. The strongest piece of evidence to suggest this? Since 2012, Mark Barberio is the only defenseman besides Anton Stralman to skate with Victor Hedman and improve Hedman's Corsi For%. Hedman, traditionally the driver on Tampa's blue line, saw an absurd 66.5% Corsi For -- a +16% improvement -- when he skated with Barberio in about 130 5v5 minutes over two seasons.

Barberio often draws criticism for turning the puck over and, admittedly, often fails the eye test. He doesn't look very strong, fast, agile, or creative, especially when compared with how he looked as part of Tampa Bay's top AHL affiliate, be it the Norfolk Admirals or the Syracuse Crunch. But the bottom line is the Lightning control the puck when he's on the ice and Barberio has been toiling away as a spot-duty 7D or fill-in for too long. With Radko Gudas out, it's time for the organization to give the 24 year old, who signed another 1-year deal last summer, a real chance to skate in the top-4 -- perhaps alongside Victor Hedman -- either until Gudas returns, a trade is made, or Barberio proves that the top-4 is where he belongs.