Mark Kastelic has quickly become one of the most pleasant surprises for the Boston Bruins this season, and now an insider is suggesting his role could be much bigger than originally expected.

Acquired from the Ottawa Senators in 2024 as part of the Linus Ullmark trade, Kastelic was initially viewed as a bottom-six depth forward. But after a breakout campaign, Bruins insider Fluto Shinzawa of The Athletic believes the 25-year-old has the tools to develop into a top-six forward for Boston.

"Kastelic scored a career-high 12 goals, became a regular penalty killer and even found a role as an overtime faceoff specialist," Shinzawa wrote. "Willing and able to fight anyone, including heavyweight champion Mathieu Olivier in a critical comeback win against the Columbus Blue Jackets, it's not a stretch to think he can be a No. 2 right wing because of his shot, skating and fearlessness."

Kastelic's emergence would be a massive boost for Boston, adding both skill and toughness to a forward group that surprised many by making the playoffs this season. Even if he sticks on the third line, his presence makes the Bruins deeper and more versatile.

In 82 games this season, Kastelic posted 12 goals and 10 assists for 22 points. He's signed for two more years at a team-friendly $4.7 million total deal—a bargain if he continues his upward trajectory.

For a Bruins team looking to balance grit with scoring, Kastelic's development could be the kind of internal growth that keeps the lineup competitive without breaking the bank.