Why Marco Sturm is making some changes for Game 4

Sabres coach Lindy Ruff made three lineup changes after losing Game 2, including going to a new starting goalie in Alex Lyon, and it paid off in a 3-1 Buffalo win in Game 3 Thursday night at TD Garden.

Bruins coach Marco Sturm isn't about to make a goalie change – Jeremy Swayman has been Boston's best player in this series – but it does appear he'll be making two swaps for Sunday afternoon's Game 4.

At Saturday's practice at Warrior Ice Arena, Lukas Reichel replaced James Hagens at third-line left wing, and Jordan Harris replaced Mason Lohrei as Hampus Lindholm's partner on the second defense pair.

Let's start with the change up front. There's no way around it: Hagens has struggled the last two games. Buffalo's first goal in Game 3 deflected off his stick after he got a bit lost on the backcheck. He's also had a couple turnovers in the offensive zone, including on the power play. And, he whiffed on a golden opportunity with a half-empty net on one of the Bruins' best power-play chances.

The kid is 19 years old. He's played five NHL games. Some hiccups had to be expected. And if this were the regular season, Sturm would probably give Hagens a longer leash to work through them. But it's not the regular season; it's the middle of a first-round playoff series, and Sturm has to do whatever he thinks is necessary to win a crucial Game 4 and even up this series.

Asked about Hagens after Saturday's practice, Sturm made sure to pump Hagens' tires and said Hagens has already given the Bruins more than Sturm thought he would. He also said he'll use Hagens again in the "near future," so the door is open for this to just be a one-game break.

What's more interesting than Hagens coming out is who's going in. Reichel and his speed certainly provided a spark when he first got to Boston in March, with three points in his first five games, but then his play trailed off down the stretch.

Mikey Eyssimont and Alex Steeves were the other options to draw in, and both had stronger finishes to the regular season than Reichel (at least to my eyes). Eyssimont could have added more jam and pestiness while still bringing some speed, while Steeves could have been more of a forechecking, physical option.

Sturm, however, is opting for the pure speed and skill of Reichel, saying it's something the Bruins have been lacking.

What's just as interesting as the third-line swap is that there won't be any changes to the first line, at least to start the game. The Morgan Geekie-Elias Lindholm-David Pastrnak line had a really good Game 1, an OK Game 2, and a tough Game 3 – both at 5-on-5 and on the power play. Lindholm ultimately got demoted from the first power-play unit late in the third period.

Sturm could have flipped Lindholm with Fraser Minten, who has played well with Pastrnak at times this season, or even fully reunited the original "kids line" by putting both Minten and Marat Khusnutdinov with Pastrnak. Instead, Sturm is issuing a challenge to his first line to respond and step up in Game 4, just as he did with his second line after Game 1.

On the back end, Lohrei also really struggled in Game 3 – and for most of the series, to be honest. He's a team-worst minus-4 in the series, tied with usual D partner Hampus Lindholm. Buffalo's forecheck has been a problem for him, as he's struggled to make clean plays under pressure.

Harris has played just three games since November after missing a large chunk of the season with a fractured ankle suffered in October. That makes him an interesting choice to go in, especially with the more experienced Henri Jokiharju also an option, but it's worth noting that Harris did look really solid in the second-to-last game of the regular season in Columbus. He also played with Lindholm a week before that in Tampa.

Sturm cited Harris' skating ability as the biggest reason he's going in, as the Bruins will hope that mobility helps them exit the defensive zone a bit cleaner.

Puck drop for Game 4 is set for 2 p.m. Sunday afternoon at TD Garden.