The Lightning avoided a scare at the start of the playoffs when Victor Hedman was able to suit up despite leaving the final round robin-game against the Flyers with an apparent ankle injury.But now, Tampa Bay might have concerns about another defenseman.Ryan McDonagh got tangled up with Boston’s Connor Clifton as the Bruins defenseman made his way down the slot early in the third period of Game 1 of Sunday’s conference semifinal in Toronto.Clifton and McDonagh got back up, but McDonagh’s next shift lasted only 14 seconds. He left down the tunnel soon after his shift and did not return for the remainder of the Lightning’s 3-2 loss .Head coach Jon Cooper did not have much of an update on McDonagh on Monday morning. Cooper said the blueliner would not participate in Monday’s optional skate, but neither would many other players.“He’s not going on the ice (Monday),” Cooper said. “As for the game, let’s just wait until (Tuesday).”Cooper reasoned that so few players skating Monday might have to do with back-to-back games scheduled for Tuesday and Wednesday. Practice time at this point in the season is more about getting out on the ice to touch the puck, he said.McDonagh’s impact on the Lightning’s defense cannot be understated. His time on ice trails only goaltender Andrei Vasilevskiy and Hedman — a Norris Trophy finalist — on the Lightning roster.He has been able to take some of the pressure off Hedman on the back end since his arrival in 2017-18. Hedman’s average time on ice went from 25:51 that year to 22:46 in 2018-19.Hedman’s average time on ice has since increased, but Mikhail Sergachev has stepped into a larger defensive role, too, his ice time increasing from 17:55 last year to 20:22 this season. Sergachev has played a key role on the power play, shifting between the top and second units throughout the year.McDonagh also plays a large role on the penalty kill, which has been put to work 34 times this postseason, including round-robin play. Tampa Bay has killed 29 of those penalties, including 2 of 3 in Game 1.McDonagh is conscientious about getting the little things right and working the grittier aspects of the game that are sometimes overlooked.He and defense partner Erik Cernak have been known in particular for their shot-blocking abilities. The two combined for six blocks on Sunday. In fact, McDonagh averaged 2.03 blocks per game this season and had at least one in all but five games.“He’s kind of our calming factor on the back end,” fellow defenseman Kevin Shattenkirk said. “Obviously, he has to play against teams’ top lines every night and get put out in defensive-zone situations, penalty kill. Maybe not the areas that are the flashiest, but I think his commitment to doing all of those little things well, his commitment to blocking shots, being responsible defensively (helps him elevate the team’s defense).”If McDonagh is unable to play Tuesday, Luke Schenn or Braydon Coburn could make their 2020 postseason debut. Schenn has skated in multiple pregame warmups, while Coburn skated before Game 5 against the Blue Jackets on Wednesday.Schenn skated in 25 games with the Lightning this season, Coburn in 40. Most of their time came at the beginning of the season and right before the season was paused in March due to the coronavirus.Before the league’s hiatus, McDonagh was battling back from a lower-body injury he sustained blocking a shot with his right leg against the Penguins on Feb. 6. He returned on March 8, two games before the league shut down.McDonagh’s impact isn’t limited to statistics — he’s also stepped up as a leader, especially in the absence of captain Steven Stamkos.“(McDonagh’s) a quieter guy, and when he speaks in the locker room, it kind of carries a weight,” Shattenkirk said. “So when he’s doing all of those things, we feel like we all have to step in, step up and chip in as well and make sure that we’re following in his footsteps.” Contact Mari Faiello at firstname.lastname@example.org . Follow @faiello_mari .