The Atlantic Division has long been dominated by the Florida Panthers, Tampa Bay Lightning, and, if we're strictly talking about the regular season, even the Toronto Maple Leafs. But the division could be in for a shakeup this season, and the Ottawa Senators are quietly positioned to capitalize.

The biggest news comes out of Florida, where the defending Stanley Cup champions face a couple of massive injury setbacks. We already knew that Matthew Tkachuk, who powered through a torn adductor and sports hernia last season, will miss significant time – maybe a couple of months or more.

Now, the Panthers will also be without their captain, Alexander Barkov, probably for the full season, following a knee injury this week. In terms of impact on the team, this is in the same realm as the notion of the Senators losing Brady Tkachuk for the season (knock on wood).

Barkov and Matthew Tkachuk rank among the NHL’s elite, and their absence leaves Florida’s roster suddenly vulnerable. As it was, the Panthers only finished a point ahead of the Sens in last year's regular season. It makes you wonder if the physical strain of going to three straight finals is starting to take its toll.

Of course, they'll talk about next man up, and they can use Barkov's LTIR cap savings to try and patch things as best they can, but Paul Maurice was right on the money with his statement on Friday:

"At the end of the day, I know there’s the idea of next man up, I get all that, but there’s not a next man for Barky's skates.”

Even with reinforcements, the loss of Tkachuk and Barkov is a seismic blow in Sunrise.

Toronto, another team that finished ahead of Ottawa in the Atlantic last year, and the one that eliminated them from the playoffs, isn’t exactly at full strength either. The Leafs lost Mitch Marner to the Vegas Golden Knights in free agency, a departure that removes both an elite offensive threat and Auston Matthews' partner in crime. While Toronto has added some new faces, none can fully replace Marner’s impact.

The Leafs also have goaltending concerns at the moment. Joseph Woll stepped away for personal reasons earlier this week. His return date is unknown, but the Leafs suddenly signed James Reimer on Friday, which might hint that Woll may need significant time away. Despite the timing of the signing, head coach Craig Berube said this week it's merely a signing for depth. 

Tampa Bay, historically a dominant Atlantic team, enters the season with its own questions. Andrei Vasilevskiy, the Lightning’s star goaltender, has been limited in training camp due to injury. While the team insists he’ll be ready for opening night, he continues to receive treatment.

Additionally, after 11 years of Atlantic division excellence, which includes ten playoff appearances, six conference finals, four Cup Finals, and two Stanley Cups, Tampa Bay’s window can’t remain open forever... can it?

Meanwhile, the Senators are trending upward. Last season, Ottawa returned to the playoffs for the first time in eight years. Their young core is entering its prime, and the experience of last year’s first-round exit should provide valuable lessons.

With a full season under the new coaching staff’s systems and the familiarity that goes with that, the team is poised to hit the ground running. While they do have injury concerns of their own — most notably Drake Batherson and Nick Jensen — Ottawa looks capable of challenging for the top of the Atlantic.

With major players missing from the division’s traditional powerhouses and a young, hungry Sens team eager to prove itself, the division suddenly looks a lot more up for grabs.

So, buckle up: the Atlantic waters are about to get choppy.