Boston Bruins defenseman Kevan Miller fights Washington Capitals left wing Aaron Volpatti. (Charles Krupa/AP)

Playing a lineup filled mostly with AHL regulars on Monday night in Boston, Washington fell, 3-2, in overtime to the Bruins, who dressed many of their NHL workhorses.It was Washington’s fifth consecutive overtime game of the preseason, but the first decided without a shootout.

The Bruins’ Chris Kelly scored the game-winner into an open net 3:39 into the extra session after the puck redirected off the skates of Capitals defenseman Jack Hillen.

Zdeno Chara, Boston’s towering defenseman, scored a pair of power-play goals in regulation, which was punctuated by five fights.  Defensive prospect Connor Carrick scored on a power-play blast for the Capitals, and veteran winger Martin Erat redirected the puck past Tuukka Rask (12 saves) to tie the game in the third period. Braden Holtby, playing his first full game of the preseason, finished with 35 saves for Washington.

Five thoughts on the overtime loss:

1. First impression of Grabovski. Monday night marked the first time Mikhail Grabovski skated with his new team in a preseason game and while there is chemistry to be sorted out with his linemates, there were glimpses of what the playmaking center will bring.

He helped set up Martin Erat’s game-tying goal in the third when he curled off the wall with the puck and skated to the top of the circles, attracting the attention of four Bruins. Grabovski also showcased his vision for creative plays and passes, but his linemates weren’t always on the same wavelength. He’s eager to develop that familiarity, though.

“I know we can play better. We need a little more chemistry, to play together in more games. It’s all about time,” Grabovski said. “Need to practice together more, play games, then we can understand each other. Maybe I need to pass different passes now than I pass in Toronto because every player’s different. I try to find the right way.”

2. Developing chemistry. It’s going to take a few games for Grabovski, Brooks Laich and Troy Brouwer to function as a cohesive unit. That much was made evident by the occasional miscue on a pass or when the forwards were caught in the same area of the ice, not in tune with where their teammates would be.

This was an important step in the process, though. While the trio practiced together for five days before this game, there are certain situations that aren’t simulated in drills.

“I learned Grabo really likes to dish the puck wide,” Laich said, detailing some of the aspects of Grabovski’s game he hadn’t previously discovered. “In the defensive zone he’s a guy who likes to get the puck and skate it out of the corner, he’s got that ability, rather than making a pass instantly to a winger. He likes to get his feet going, so for myself I have to reroute a little bit instead of slashing across the ice all the time, reroute and come back to my side. Little intricacies like that that we’ll pick up the more we go through.”

3. New fighting rule. Among the many new rules for this season is one that penalizes players for removing their helmets before a fight. It’s a trickle-down effect of making visors mandatory, except for those with at least 26 games of NHL experience who are grandfathered in and allowed to choose if they will wear the extra gear.

With the visor mandate, the league had to abolish the penalty for fighting while sporting a visor. But it wanted to discourage players from taking off their helmets, which kept them from punching a solid piece of impact-resistant plastic but also made them more vulnerable to concussions.

Here’s the official text of the rule:

46.6 Helmets – No player may remove his helmet prior to engaging in a fight. If he should do so, he shall be assessed a two minute minor penalty for unsportsmanlike conduct. Helmets that come off in the course of and resulting from the altercation will not result in a penalty to either player.

4. But does it solve the problem it’s intended to fix? The league’s intent is a valid one in attempting to minimize the risk of concussions, but in the earliest stages of enforcing the rule there appear to be some unintended issues stemming from it.

Monday night, Capitals winger Aaron Volpatti, who doesn’t wear a visor, was challenged to fight by Bruins prospect Kevan Miller, who does have the shield. There was an odd pause before they started swinging, though, as the two players tried to determine if they could avoid an additional minor penalty by knocking the other’s helmet off. (New Jersey’s Krys Barch and the Islanders’ Brett Gallant discovered that loophole last week.)

“You’re getting yourself jacked up, you’re getting in a scrap. It was weird. I didn’t really know what to do. I wanted him to have his shield off, I don’t want to punch a shield, but at the same time I want to keep my helmet on,” Volpatti said. “I think you ask any of the guys in the league without a visor, they want to keep their helmet on because guys are whacking their heads on the ice.

“I fell on the boards and went back and if he has more weight on my upper neck or head it’s dangerous,” Volpatti continued. “I don’t really know what the solution is but I respect the league. I know what they’re trying to do and implement but there’s repercussions to everything, I guess. You can’t please everyone. I hope there’s something we can kind of figure out here.”

What will happen in the future when all players wear visors? No one wants to punch a shield, but players will have to pick between that or risk not wearing a helmet. Will it help push fighting out of the league? Or will a company create an easily detachable visor for the best of both worlds? While the role of an enforcer seems to be diminishing throughout the NHL, it’s tough to say when or if the league will reach a point where it’s no longer part of the game.

5. Carrick contract and goal. Monday was a pretty good day for Carrick. In the afternoon, he signed a three-year, entry-level deal and earned some more praise from Coach Adam Oates. Hours later against the Bruins, the 19-year-old blue-liner scored his first goal of the preseason on a blast from the point on a power play to put the Capitals up 1-0.

Pleased to have the commitment from the Capitals, the 2012 fifth-round pick has become gradually more comfortable in each preseason appearance.

“There’s been a couple plays after each game I’m like, ‘Ah, I would like that one back’ because as an offensive D you’ve really got to be comfortable at the level you’re playing at,” Carrick said. “It takes time to get used to the pace and know who you’re playing against. I’m a guy who I get better the more I know who I’m playing against. The fact that it’s been someone different, someone I’ve never played against every night has made it difficult but I’m trying, I’m working hard and I think I’m getting better. It was a lot of fun.”