With Mikhail Sergachev making an early mark on the Tampa Bay Lightning’s blue line, he doesn’t seem to be going anywhere. Since the off-season trade for Sergachev, it was apparent that the Lightning would likely carry eight defensemen on the roster at least for the early part of the season. Now that Sergachev has made it to the ten-game mark that kicks in the first year of his entry-level contract, the rumors have already started about both Slater Koekkoek and Andrej Sustr potentially being traded.

The Vegas Golden Knights’ excess of defensemen has made the market rather saturated for third-pair defensemen, which both players are at this point in their careers. Vegas has also waived Jason Garrison and Griffin Reinhart in the past couple days and neither one was claimed. The availability of such defensemen does make trading either Lightning blueliner more difficult. Koekkoek’s value has also been depressed by his slow development, though the potential for him to break out as a top four defensemen in the next few years is still there. Sustr is on an expiring contract and will be an unrestricted free agent next summer. His inconsistent play and his ceiling as a third-pair defensemen also limits his value.

But I’m going to make a case to keep both defensemen.

Since the third game of the season, head coach Jon Cooper has gone with an eleven forward, seven defensemen lineup. It’s hard to argue with the results since the team is 8-1-1 in that configuration.

It has allowed the Lightning’s top six forwards to get extra time on ice by double shifting with the third line of Alex Killorn and Tyler Johnson. It’s also given Cooper the flexibility with that third line to send them out with an offensive forward to spark some chances or with a defensive forward for a shutdown shift.

On the back end, it’s kept the minutes of everyone but Victor Hedman and Anton Stralman at levels that are reasonable for their skill levels and abilities, and allowed the former two players to play more minutes. Rick Bowness can also control the zone starts for his younger defensemen and play with matchups against opposing lines. On the road, it also makes it harder for opposing coaches to target one specific pairing. If Bowness sees that they are, he can easily shake up that pairing or change how they are deployed to counteract their strategy.

As I said before, Koekkoek still has time to progress and become a better defenseman. While there isn’t a clear spot for him in the line-up beyond a seventh defenseman right now, there may be one next year or the year after depending on potential roster shake-ups.

Sustr is also an experienced defenseman that is approaching 300 games played in his NHL career plus another 46 playoff games. I’ve been asked several times on Twitter what Cooper sees in Sustr. The reality is that he is a serviceable third-pair defenseman with experience. Yes, he makes mistakes but I believe, like Matt Carle before him, that his mistakes are magnified by fans way out of proportion to other defensemen on the roster.

The big positive to keeping both defensemen is defensive depth. GM Steve Yzerman learned his lesson during the 2013-14 season about defensive depth and its importance, especially in the playoffs. During the 2013-14 season, the Lightning were forced to use 12 different defensemen throughout the season. In 41 regular season games, the Lightning played seven defensemen. Of the 12 defensemen entering the season, seven had fewer than 82 games of experience and only four had more than 250 games of experience.

The Lightning’s position on the blue line this season isn’t much different with five defensemen who had more than 250 games played and three who had less than 82 games played in their careers entering the season.

But looking beyond the defensemen currently on the roster, if one was traded and two injuries on the blue line forced a recall from the Syracuse Crunch, there’s only one player with any NHL experience: Jamie McBain. The right-hander has 348 games of NHL experience in his career, mostly as a third-pairing player. No other Crunch defenseman has played a game in the NHL. The next most experienced pros are 25-year-old Reid McNeil with 238 AHL games, and 27-year old Mathew Bodie with 221 AHL games.

The other five defensemen in Syracuse are third-year pro Daniel Walcott, second-year pros Ben Thomas and Dominik Masin, and rookies Erik Cernak and Matthew Spencer. Masin, Cernak, and Spencer were all second-round picks, but the other two were late-rounders. Thomas made a lot of noise late last season for the Syracuse Crunch as an offensive-defenseman, but he has a lot to work on with his defensive game to become an NHL defenseman.

Cernak, acquired in the Ben Bishop trade last season, has been turning heads in the AHL so far, but is still a ways from being NHL ready. Walcott is more likely to make the NHL as fourth line forward than as a defenseman and Masin had a rough rookie season. Spencer has only played in one game so far this season for the Crunch and only two AHL games overall.

Beyond McBain, the depth gets weak very quickly. The Lightning are not in a good position to deal with trading a defenseman and then losing two or three to injury. While it’s not highly likely that happens, it is within the realm of possibilities. And I don’t think that’s a position that Yzerman wants to find himself in again.