Boston Bruins coach Jim Montgomery is searching for reasons for his team’s lackluster 7-7-2 start.

“We’ll look at what we’re doing sports science-wise, but we’ll come up with answers,” Montgomery said. “Right now, I don’t have an answer for you.”

The exploration will continue when the Bruins visit the struggling St. Louis Blues on Tuesday night.

Boston is coming off a 3-2 overtime loss to the visiting Ottawa Senators on Saturday night. The Bruins, 1-1-1 in their last three games, were outshot 12-0 in the third period.

“It’s up for you guys to figure that out and come up with a reason,” Montgomery told reporters after the loss. “We just weren’t good enough. You guys can write what you guys think is the malaise on the team and what’s going wrong. We’re just not playing good enough.”

Captain Brad Marchand noted that Boston is reacting to the play rather than initiating it.

“Sometimes when you lack confidence or you’re overthinking, your execution is slow,” Marchand said. “We need to get out of our heads. Stop thinking and start playing. It comes down to will and compete at this point. We need to understand we need to be better. That’s part of it. Sometimes when you’re thinking about where you’re supposed to be, you’re half a second late. That’s too slow in this league.”

The Bruins are near the bottom of the NHL offensively, averaging 2.5 goals per game. Their power play is converting at 12.5 percent, tied for second worst in the league entering Monday.

Fortunately for the Bruins, they face the team with the NHL’s least effective power play — the Blues.

The injury-depleted Blues are connecting on just 10.8 percent of their power-play chances and are just head of the Bruins in goals per game (2.53).

Playing without top center Robert Thomas (broken ankle) and top-four defensemen Philip Broberg and Nick Leddy (both sidelined by lower-body injuries), the Blues have fallen into a funk.

The Blues’ 8-1 loss to the Washington Capitals on Saturday night was their fifth defeat in their last seven games, dropping them below .500 at 7-8-0.

St, Louis collapsed in the third period, allowing five goals.

“You can’t sugarcoat it when you let in eight,” Blues captain Brayden Schenn said. “It just boils down to being in a hockey game, being able to come back from 3-1, to letting in five in the third period. It’s just absolutely unacceptable.”

It was the second time in two weeks the Blues suffered an 8-1 loss. After they lost by seven at Ottawa on Oct. 29, they rebounded to win two of their next three while allowing two goals per game over that span.

“We bounce back with some good efforts but we haven’t been able to sustain it,” coach Drew Bannister said. “We have to be able to sustain playing better hockey. We can’t take one or two steps forward and then keep taking these steps back. Our consistency when we’re playing well, we have to be able to maintain that.”