Capitals defenseman Matt Irwin was one of the 20 players who dressed for Tuesday's loss to the St. Louis Blues. He did not play, however, until the final shift of the game. His stats in the final box score read 29 seconds of time on the ice and that's it.

So what happened?

Irwin came into the game as the team's seventh defenseman with the Caps having to skate a lineup down a forward. That meant he was always slated to see very little time on ice.

In Monday's trade deadline, the Caps added forwards Marcus Johansson and Johan Larsson. Johansson was able to play Tuesday, but Larsson is still recovering from a sports hernia and is not yet ready to play. Nic Dowd and T.J. Oshie, meanwhile, are also injured. This put the Caps in a bind on Tuesday as they had only 11 forwards available and zero cap space. So the Caps did the only thing they could, they dressed 11 forwards and seven defensemen.

"This is what we were allowed to do based on the cap," Peter Laviolette said.

With no cap space, the team could not make a recall. Even with emergency recalls, the team still has to remain cap compliant. Washington does have two players who are waiver exempt they could have reassigned on Tuesday to open up a spot on the roster, but that was essentially not an option. The issue there is that one of those players is Connor McMichael -- sending down a forward when you are a forward short does not help the problem -- and the other is Martin Fehervary -- one of the team's top defensemen and someone too valuable to take out of the lineup just to balance out the forward lines.

In that sense, playing 11 forwards and seven defensemen was the team's best option. But doing so also left the team shorthanded.

Laviolette does not like mixing his defensive pairs. We saw this last season when circumstances dictated the team dress seven defensemen and Jonas Siegenthaler only managed 28 seconds of playing time.

"So it becomes really difficult juggling seven defensemen," Laviolette said following that game. "You do it because if you have an injury or if something pops up on the bench, you dressed the player and you dress to the maximum of 20. So this had nothing to do with Jonas at all and we were just playing the six defensemen that we’ve been going with. It’s difficult to roll seven. It takes people out of the loop and they lose rhythm with different partners.”

We saw that philosophy on display again on Tuesday as Irwin skated just the final 29 seconds of the game.

In short, the Caps played with 11 forwards because they had no choice, but did not utilize Irwin because Laviolette does not like mixing his defensive pairs over the course of a game. The result was a shorthanded Caps team and an odd stat line for Irwin.