The one-year contract is reportedly worth $1.95 million, per CapFriendly.
"Alexander is a dependable young defenseman who adds size and physicality to our lineup," said GM Dale Tallon.
Petrovic, 26, appeared in 67 games for the Panthers last season, recording two goals and 13 points and had a team-leading average of 2.1 hits per game.
The former second-round pick was one of four Florida defensemen protected in last year's expansion draft, leaving forwards Jonathan Marchessault and Reilly Smith exposed.
Ennis was a first-round draft selection by the Buffalo Sabres in 2008, netting 20 goals and 49 points in his first full season. He was traded to the Minnesota Wild in 2017, along with Marcus Foligno, in a deal for Jason Pominville and Marco Scandella.
Last season, the 28-year-old Ennis tallied 22 points, including three game-winning goals. The Alberta native joins the Maple Leafs with 258 career points in 492 games.
Strome's new deal, which carries a cap hit of $3.1 million, will pay him $3 million next season and $3.2 million in 2019-20.
Strome managed only 13 goals and 34 points while appearing in all 82 games for Edmonton last season. He was acquired from the New York Islanders in exchange for Jordan Eberle last June.
Longtime NHL winger Alex Burrows has called it a career, announcing his retirement after 13 seasons.
"I’m happy with my career and have some great memories," Burrows told NHLPA.com. "I met some wonderful people over the years. I’ll miss my teammates the most. The amount of fun we had working on our craft, the time we spent together away from the rink, the time we went through adversity together - those are things that I’m going to miss."
Burrows was placed on waivers for the purpose of a buyout by the Ottawa Senators earlier in the offseason after signing a two-year deal with the club in 2017.
Shortly after the announcement, the Montreal Canadiens revealed Burrows will join their AHL affiliate, the Laval Rocket, as an assistant coach.
The 37-year-old wasn't drafted, and he broke into the league with the Vancouver Canucks during the 2005-06 season after bouncing around in the ECHL and AHL. His best season came in 2009-10 when he recorded 35 goals and 32 assists.
Overall, Burrows appeared in 913 NHL contests, registering 409 points and 1,134 penalty minutes.
Looking ahead to the next NHL season, there are already some fantasy-relevant roster situations worth monitoring.
While there are obvious breakout candidates and rookies likely to make an impact, several intriguing players aren't yet cemented as must-draft options, but could rise up fantasy rankings by summer's end.
Here are three players to keep an eye on as the new season approaches:
Thomas Chabot
Chabot would have much more value playing alongside Erik Karlsson, but that's looking less likely by the day. However, the 21-year-old could still be worth a look if his superstar partner is dealt.
Even if the Ottawa Senators get a player like Mikhail Sergachev in a Karlsson trade, Chabot will be in line for a big boost in ice time, and his upside is undeniable.
On the other hand, the Senators won't be good in 2018-19, and how he handles an expanded role without much help around him remains to be seen.
Chabot is at the very least worth adding to your watch list as the Karlsson situation continues to unfold, and his stock could improve as the season approaches.
Elias Lindholm
Lindholm looked like a very solid fantasy option after being traded from the Carolina Hurricanes to the Calgary Flames on day two of the draft last month, but then the Flames signed veteran sniper James Neal to a five-year deal on Monday.
Without Neal, Lindholm would probably have had the inside track for first-line duties alongside Johnny Gaudreau and Sean Monahan. That assignment would've made drafting him a no-brainer. Now, though, it's looking like Lindholm could be relegated to second- or third-line duties.
That would mean lining up with Matthew Tkachuk and Mikael Backlund on the second forward unit, or potentially with the likes of Sam Bennett and Derek Ryan on the third. Also, Lindholm's power-play output would take a big dip if he ends up on PP2 instead of PP1.
Flames head coach Bill Peters, who had Lindholm with the Hurricanes, might even opt to balance things out by putting Neal on the second line and his former Carolina forward on the first.
Lindholm's fantasy impact will come down to his usage. The latter isn't entirely clear yet, so he's simply worth watching for the time being.
Jesse Puljujarvi
Puljujarvi's role for next season isn't clear yet and won't be for a while. However, he's worth flagging this summer, and watching when training camp opens in September.
The young Edmonton Oilers winger might start the season on the club's third line, which would severely limit his fantasy value, but he can avoid that fate and boost his production potential by securing a spot on the second unit with Leon Draisaitl.
He could even end up getting some ice time with Connor McDavid, though Ty Rattie will likely receive the top-line assignment first (and rightfully so after Rattie's success in that spot in 2017-18).
Pujujarvi only potted 12 goals in 65 games this past campaign, but 10 of those goals came at even strength, which bodes well for the 20-year-old's future production.
If he ends up getting time on the power play (especially on the first power-play unit that should feature both McDavid and Draisaitl), Pujujarvi would warrant fantasy roster consideration. Even getting into Edmonton's top six would be enough to make him relevant in most leagues.
Dreger notes that the New York Rangers may also be involved in some capacity as the Lightning will need to free up cap space if they are to bring on Karlsson's $6.5-million cap hit.
Karlsson will become an unrestricted free agent after this season and is expected to sign a contract similar to that of Drew Doughty of the Los Angeles Kings, who just fetched an eight-year, $88-million extension.
Another challenge for the Lightning is that a number of their players have no-trade clauses.
Tyler Johnson, Dan Girardi, Alex Killorn, Ondrej Palat each have a full no trade right now. Ryan Callahan, Braydon Coburn, Anton Stralman each have a 16-team trade list. 🌈
Earlier this week, it was reported the Dallas Stars had become the front-runners to land Karlsson. The Columbus Blue Jackets had also reportedly shown interest, but the asking price was believed to be too high from their perspective.
"Trevor was a steady presence on our blue line last season," general manager Don Waddell said in a release. "He's shown progression each year of his NHL career, and is a well-liked player in our locker room."
News of the signing comes shortly after it was announced that Van Riemsdyk filed for arbitration. The 26-year-old elected for arbitration prior to Thursday's 5 p.m. ET deadline, before agreeing to the new contract, according to TSN's Frank Seravalli.
Van Riemsdyk put up three goals and 16 points in his first campaign with Carolina after spending his first three seasons with the Chicago Blackhawks.
The 24-year-old is coming off his fourth season with the Lightning. He finished 2017-18 with five goals and four assists over 56 games. Paquette also recorded a goal and an assist in 17 playoff games this spring.
The fourth-round pick in 2012 was a restricted free agent, and he received a slight raise from his previous two-year deal that carried a cap hit of $812,500.
