The Lightning could very well add another defenseman by Monday's trade deadline, whether it's one of the bigger fish, such as Erik Karlsson and Ryan McDonagh, or a depth piece, such as Mike Green.Either way, one addition won't automatically cure some of the team-wide defensive issues."If we switch out a couple guys, the rest of the team is still here," defenseman Anton Stralman said. "And we have to fix it."In the big picture, this is far from panic time. The Lightning is in first place in the Atlantic Division by four points over the Maple Leafs, whom it faces Monday in Tampa. It's encouraging that Tampa Bay is finding ways to win, including sweeping a three-game road trip that concluded Saturday, without playing its best hockey.But as rivals continue to step up at the deadline – the defending two-time Stanley Cup champion Penguins have added center Derick Brassard, and the Bruins have acquired wing Rick Nash – the Lightning knows its current play isn't sustainable come playoff time."The first round of the playoffs is always the toughest," associate coach Rick Bowness said. "You're playing a team that had to fight six to eight weeks to make it. They're in battle mode for two months. And there's no magical switch, 'Okay, we're going to cruise into the playoffs.'"When there's upsets, it's usually because of the bad habits creeping in during the last month on a team that has got a secure playoff spot. And it's our job as coaches to not allow that to happen."The good news for the Lightning is that it has a favorable schedule over the next month, with 10 of its next 11 games at home. That means more practice time, such as the 70-minute workout it had Friday in Montreal. Practicing has been hard for the Lightning during its recent stretch of 18 of 25 games on the road."The big thing is you've got to make yourself sharp," coach Jon Cooper said. "When you go so long without practicing, you can say rest is a weapon all you want, but you need practices to stay sharper."You can just tell we're not executing breakouts the way we normally do, just those little things that add up when you don't practice. The players aren't looking forward to it . . . but we'll have a lot more practice time. It'll be good for us to hopefully play deep into the spring."Bowness said the Lightning is spending way too much time in its zone, a result of turnovers and not winning enough battles."Instead of going out on attack and using our speed, we're playing defense," Bowness said. "We're built for speed; we're built for attack. The five guys on the ice have to work together, harder at both ends."And when the Lightning takes a lead, it often tends to gamble, trying to score more instead of locking the game down. You saw that in Thursday's 4-3 win in Ottawa, where Tampa Bay had to hold on for dear life."It's a mentality," Tyler Johnson said. "It's staying in your structure, and that's a choice. Our game is being aggressive, forcing things. But it's about making the right decisions. It's about maybe not making that high-risk play, and for whatever reason, we feel like sometimes we try to make that play that, quite frankly, at the time we don't have to. We have to do a way better job of realizing when we can do it and when we can't. We're learning, but it's getting to a point where we've got to be bearing down."Adding a Karlsson or a McDonagh would help. But it sounds like a potential Karlsson deal is far from a given. It would be complicated and costly, involving three or more teams, especially if Ottawa wants to include wing Bobby Ryan's contract ($7.25 million through 2021-22). Lightning general manager Steve Yzerman has said he does not want to deal from his current roster, but the Senators are pushing for a player on it, Canada's Sportsnet TV network reported Saturday. Tampa Bay may not be willing to pay that price.As for McDonagh, the Lightning isn't on his 10-team no-trade list. But he has other suitors, too, including the Leafs. That Green has missed the past five games entering Sunday's game against the Rangers with a neck injury (suffered against Tampa Bay) probably hasn't helped his trade situation.There's also a chance the Lightning could help itself defensively by acquiring a bottom-six center. No matter what, though, a deadline move would be just a boost, not a solution."We've just been inconsistent with everything we're doing," Bowness said. "That's the bottom line. We can score. We get great goaltending. But little things slip, there's no question."