TAMPA — When Lightning general manager Steve Yzerman brought the band back together last summer, he was celebrated. Tampa Bay kept its core together for the third straight year and was labeled a Stanley Cup favorite.But starting at Wednesday's trade deadline, you may begin seeing changes to a familiar roster. And we're not talking about just the possible departures of pending unrestricted free agents Ben Bishop and Brian Boyle.With the expansion draft and another salary cap crunch coming this summer, Yzerman said some decisions have to be made for next season and beyond, not just for this season's playoff push. Still, his evaluation of the Lightning's playoff chances has to be a factor, as does the timeline of Steven Stamkos' return from November knee surgery.Yzerman has said he's between being a buyer and a seller. Asked if he had any untouchable players, Yzerman explained his philosophy:"We have our core, and I want to try to add to that core. Over time, your core has to change. That's just the reality. You can't afford to keep everybody. Are players untouchable? Yes. Because I want to build around the core. But at some point to address the needs, if there's something really good out there, you're going to probably have to give up something really good to do that."The Blackhawks, for example, were forced by cap issues to overhaul their roster a lot in the process of winning the Stanley Cup in 2010, '13 and '15. Former Chicago forward Patrick Sharp, traded to the Stars in July 2015 for cap reasons, joked that you could create an All-Star team from all the players who have left the Blackhawks in that time.Other teams made significant additions in seasons they ended up winning the Cup. The Kings got Jeff Carter (2012) and Marian Gaborik (2014) in deadline deals. The Penguins acquired Phil Kessel in a trade before last season, then got Carl Hagelin and Trevor Daley in deals during the year en route to the Cup. The Lightning did make a minor trade Saturday, swapping minor-league forwards with Arizona. Wing Jeremy Morin went to the Coyotes for wing Stefan Fournier.Major changes at the deadline never work, said former Rangers general manager Neil Smith, an NHL Network analyst. "But tweaking certainly works," he said. "I don't know if I'd use the word stale (with a roster). But you've got to wake everybody up with some changes to say, 'Hey, we're going to take a shot at this.' And people get excited when you do this. Like, 'Oh, my God, he's behind us, he thinks we can win.' "Smith famously dealt Tony Amonte and Mike Gartner at the 1994 deadline, helping spark the Rangers to their drought-breaking Cup victory. But Smith noted that blockbuster deals are more challenging in the cap era."You can't force it," Hall of Fame coach Scotty Bowman said.Yzerman has tried to make a significant move. He nearly dealt Bishop at last year's draft to Calgary. Six weeks ago, Blues defenseman Kevin Shattenkirk nixed a potential trade and deal extension in Tampa Bay, Canada's TSN TV network reported. But Yzerman disagrees with any assertion that his roster is stale, pointing to the emergences of rookie forward Brayden Point and rookie defenseman Jake Dotchin, and playing goalie Andrei Vasilevskiy more.But a big makeover could be coming. Here are trade deadline possibilities.Ben Bishop Why: Though the goalie hasn't closed any doors, it's hard to imagine a scenario in which the Lightning can — or would — re-sign the two-time Vezina Trophy finalist, who can be an unrestricted free agent this summer. Andrei Vasilevskiy is its future, and he is signed to a team-friendly $3.5 million cap hit for each of the next three seasons. It would be better for the Lightning to get something in return for Bishop rather than lose him for nothing. Why not: Bishop has been hot, winning his past five starts. He may be increasing his trade value, but he also might be the Lightning's best shot to climb back into a playoff spot. The only way I see Bishop getting moved by Wednesday is if the return is worthy. Bishop has a partial no-trade clause, a list of eight teams to which he can't be dealt without his permission Possible destinations : Calgary, Winnipeg (unstable goaltending, still in playoff race), Philadelphia and Islanders (could use long-term No. 1).Brian Boyle Why: The forward, 32, can be an unrestricted free agent this summer. He would be open to re-signing with the Lightning for next season, and the Lightning could be interested. But Boyle could net a relatively high trade return (as in draft picks) for a playoff-bound team needing a versatile forward and leader. Why not: The reasons that other teams covet Boyle are the ones that the Lightning would keep him. Taking away a key dressing room voice could disrupt team chemistry, and he plays in all situations. GM Steve Yzerman would have to get wowed by a deal or decide that even if the Lightning makes the playoffs, it's not capable of a lengthy run. Possible destinations: Edmonton, Toronto, Columbus. Tyler Johnson Why: The Lightning will likely have a tough time affording three key players who can be restricted free agents this summer: Johnson, Ondrej Palat and Jonathan Drouin . Drouin is a lock to be re-signed. Palat likely comes cheaper. But Johnson, arguably the team's most clutch postseason player, could price himself out of Tampa Bay's plans. Having rookie center Brayden Point emerging helps. Johnson could net a solid return via trade, either this week or this summer. Why not: With Steven Stamkos out since November knee surgery, Johnson is the Lightning's No. 1 center. Dealing him would create a ripple effect. Maybe GM Steve Yzerman can clear salary cap space between now and the summer and keep Johnson, Palat and Drouin. Possible destinations: Nashville (needs a top-six forward, been scouting the Lightning a lot), St. Louis, New Jersey, Islanders. Valtteri Filppula/Jason Garrison Why: The salary cap. The Lightning could really use the financial flexibility in coming years, and moving forward Filppula and/or defenseman Garrison could help. Filppula has one more season left at $5 million, Garrison one more at $4.6 million. The Lightning has to protect Filppula in the June expansion draft due to his no-move clause, so trading him could allow it to protect another forward. Why not: Garrison also has a no-move clause, so dealing either player wouldn't be easy. A trade or trades might require sweetening the pot with draft picks (the 2017 class is considered weak) or a prospect.Wild cardsForwards V ladislav Namestnikov, J.T. Brown and Cedric Paquette. They are unlikely to be protected in June's expansion draft, and each has just one more year left on his deal.