BOSTON — What a difference a healthy David Krejci makes.

The Bruins entered Wednesday’s game against the Philadelphia Flyers ranked second in goals scored per game and first in power-play goals, and Krejci helped Boston improve both areas in a 5-4 overtime loss at TD Garden.

Krejci extended his NHL-leading power-play scoring total to six points with an assist on Patrice Bergeron’s goal at the 17:26 mark of the first period. He followed that up by earning the primary assist on Jimmy Hayes’ second period goal, which gave the B’s a 4-2 lead.

Krejci now leads the league in scoring with 11 points (four goals, seven assists), one ahead of Dallas Stars duo Jamie Benn and Tyler Seguin. He also has a six-game point streak, which means he’s found the scoresheet in every contest this season. Only four other players have done that at this point in the campaign.

Krejci has been an important part of the Bruins’ offense since the 2008-09 season. He’s one of two Bruins to tally 70-plus points in a single season over that span (Marc Savard is the other) and has finished first or second on the team in scoring five times.

This is why losing him to injury for 35 games last season was devastating for the B’s. It was one of the main reasons why Boston’s offense fell to 22nd in goals scored in 2014-15 after ranking third the season before. The power play also fell to 18th after ranking third in 2013-14.

One of the ways Krejci helps the Bruins score at even strength and the power play is by executing successful zone entries. It’s an underrated part of his game.

He’s able to enter the attacking zone with possession and help set up scoring chances, which is more effective than dumping the puck in, chasing it and hoping to win a 50-50 battle along the boards.

Hockey analytics expert Jen Costella did a nice job of explaining this in a series of tweets Wednesday night.

Krejci isn’t the most valuable Bruins forward — that would be Bergeron — but he’s their most important offensive player. His ability to score goals, slow the game down and set up teammates for chances, in addition to his power-play skill is unmatched by any other B’s forward.

Ryan Spooner’s struggles as the third-line center and the lack of scoring production from the bottom-six as a whole also have increased Krejci’s importance.

The Bruins cannot afford to lose him for an extended period of time. They’re going to need their offense to score a lot of goals to offset the defensive mistakes being made on a nightly basis.

Thumbnail photo via Sergei Belski/USA TODAY Sports Images. NBCSN screenshot via Twitter/@PeteBlackburn