TAMPA — The Lightning extended their point streak to seven games with a win over Pittsburgh, but lost Ryan McDonagh in the process.The uncertainty around the team’s No. 2 defenseman cast a shadow over the 4-2 win. The team stepped up in his absence, particularly while killing four penalties in the third period.The Lightning managed to kill 1:34 of five-on-three, while defending a one-goal lead 11 minutes into the third period. Coach Jon Cooper called the unit phenomenal, in a moment that could have flipped the momentum of the game.“Kill it off,” Victor Hedman described the mindset of that kill. “That’s the bottom line. We got put in that situation, me (Erik Cernak) and (Anthony Cirelli) and we just have to clog up the middle and eliminate their one-timers.”The Penguins only put one shot on net, and Andrei Vasilevskiy made a big save on that chance. Not too shabby without the team’s biggest penalty killer.McDonagh blocked a shot from Penguins center Evgeni Malkin in the second period. He crouched low and took the shot off the right leg. McDonagh collapsed and then immediately skated to the bench, taking awkward long strides.He tested the leg out during the next TV timeout, but didn’t last long before heading down the tunnel toward the dressing room. Cooper didn’t have an update after the game.The extent of injuries off blocked shots can be hard to project, in part because teams typically describe them generally as lower or upper-body injuries. Sometimes it looks bad in the moment, but the player doesn’t miss a game, like when Nikita Kucherov blocked a shot against the Capitals on Dec. 14. Other times, it can keep a player out weeks, like Ondrej Palat last season.Tampa Bay has played its last two games down a defenseman after Jan Rutta was hurt sliding legs-first into the boards Tuesday.The team switched lines going into Thursday’s game, as Mikhail Sergachev had moved into Rutta’s spot in the top pair with Victor Hedman and scored the first goal of the game halfway into the first period. Braydon Coburn, who hadn’t played since Jan. 14, returned to the lineup with Kevin Shattenkirk in the third pair. After McDonagh’s injury, the defensemen all rotated.“It’s not something you want to do every game, but the guys on the back end handled it well,” Hedman said. “Coby hasn’t played in a while and I thought he had a great game, played hard and played a lot of minutes.”Hedman ate up most of the minutes Thursday, playing 27:24. The only game in which he has played more was when McDonagh was hurt on Oct. 4 against Ottawa.Thursday’s game between two hot teams battling for third in the Eastern Conference was hyped as a potential preview of the Eastern Conference Final. The Penguins had won eight of their last 10 games while the Lightning were 7-2-1.With the win, Vasilevskiy set a new franchise record as the team has earned a point in his last 17 starts.A few minutes after Sergachev got the scoring started, Steven Stamkos put the Lightning up by two. Kucherov started the play with an aggressive backcheck and fed the puck up to Stamkos, who had a two-on-one with Brayden Point. He passed to Point who sent the puck back.Malkin deflected a centering pass from Patric Hornqvist into the net midway through the second period and Cirelli immediately responded to maintain the two-goal lead.Penguins defenseman John Marino narrowed the Lightning’s lead to a single goal, when he scored off the rush after a turnover, in the opening minutes of the third period.The Lightning survived their four third-period penalties, maintaining that one-goal lead until Kucherov hit an empty-netter in the final minute. Contact Diana C. Nearhos at email@example.com. Follow @dianacnearhos .