As much as Lightning GM Steve Yzerman has been known for his middle-of-the-night deals, expect any moves he makes to go right up to the 3 p.m. Monday deadline.And what Yzerman might do ranges from the blockbuster – acquiring Senators superstar Erik Karlsson – to standing pat, believing the prices were too high.Still think there's a good chance that Yzerman will get something done, even if it isn't reeling in the big fish.Any Karlsson, 27, deal will be costly, and complicated, with it sounding like there are several other suitors involved in the sweepstakes, including the expansion Golden Knights. What's more challenging, especially for the Lightning, would be to find a third party team that could help them if the Senators demand Bobby Ryan (and his $7.25 million annual cap hit through 2021-22) be included.The Senators want a package that could include legitimate NHL players, high-end prospects and two first-round picks, according to the Ottawa Sun. Yzerman has told the Tampa Bay Times that he doesn't intend to deal from his current roster, and has been holding firm with that. Canada's Sportsnet reported over the weekend that the Senators are insisting on an NHL player like Brayden Point, Yanni Gourde or Vladislav Namestnikov.Don't envision a scenario where Point goes anywhere, with Gourde – a bargain at $1 million annually through next season – likely is a lock to stay too. Namestnikov, a restricted free agent next summer, could price himself out of Tampa Bay eventually, but he's still a key piece and well-liked player on a first-place team.Yzerman would prefer to deal from his deep prospect pool and draft picks."I really don't want to just get a player or something at all costs," Yzerman said late last week. "I don't believe in that. Obviously, if we feel we can improve our team and it gives us a better chance to be more successful in the playoffs, that would be our goal."I may not be able to do that."You might say, why not go all-in on Karlsson, even if it means giving up a roster player? The Lightning certainly could use the boost defensively, even as it's at the top of the Eastern Conference. The Bruins added a few pieces, including the Rangers' Rick Nash. The Maple Leafs acquired bottom-six center Tomas Plekanec from Montrel. The two-time Cup champs Penguins got center Derick Brassard.But Yzerman has been very clear on one thing. As much as he wants to improve his club, he doesn't believe that any move he makes will guarantee him a Stanley Cup. Yzerman has been wary of overpaying at the deadline. Just look at the Wild and Capitals, who were deadline winners last season, but failed to make it out of the second round."I can give up five first-round picks and every prospect we have," Yzerman said. "And it still won't guarantee the Stanley Cup."Sure, the Lightning has 'A' level prospects like Taylor Raddysh, Cal Foote and Boris Katchouk, not to mention Brett Howden, Anthony Cirelli and Mathieu Joseph. But any Karlsson deal would likely require five-to-six pieces going the other way.How much is Yzerman willing to pay for what's likely 1 1/2 years of Karlsson?What's Plan B? Yzerman told me last week he felt there were "very limited" fits for the Lightning at the deadline, so there's probably not a lot of targets that are in range.Rangers defenseman Ryan McDonagh seems like a strong fallback option, with several of his former teammates raving about his impact on and off the ice. The Lightning is not on McDonagh's 10-team no-trade list and would appear interested in landing in Tampa (if he's not staying in New York).Tampa Bay wouldn't be the only player on McDonagh, with the Panthers emerging as a candidate. You'd think Toronto is in the mix too. McDonagh, like Karlsson, has another year left on his contract (at $4.7 million). He's a left-shot, and a shutdown-caliber defenseman, so he'd be pricey, tool, albeit not nearly as much as Karlsson.As for fallback options, how about Red Wings defenseman Mike Green? Green, 32, intrigued the Lightning, but hasn't played since getting hurt Feb. 15 (on a hit by Tampa Bay's Adam Erne). Green is close to returning, just day-to-day, but it's uncertain how his injury impacts his value, and interest at the deadline. Green has a full no-trade clause, but has agreed to move to Tampa Bay or Washington if a deal is made, per The Athletic.The Lightning has scouted Columbus heavily all season, and defenseman Jack Johnson had requested a trade. The Blue Jackets, however, recently engaged in contract extension talks with Johnson, according to The Athletic, so we'll see if that changes his availability. The fact Columbus picked up defenseman Ian Cole today could make Johnson more expendable.Other than defense, the Lightning could use a bottom-six center/forward if one fits. Thought Oilers' Mark Letestu could have been good, but he got traded to Columbus Sunday. The Wild's Matt Cullen is still out there, if the Penguins don't snatch him up. Someone in the Antoine Vermette mold, in my opinion, would be a strong addition.We do know that the Lightning isn't one of the teams in on Oilers wing Pat Maroon, who was coached by the Lightning's Jon Cooper in Texarkana and St. Louis.Got all that? Stay tuned, as we'll provide updates on tampabay.com as soon as we have them.