Lightning coach Guy Boucher said he is contemplating life without either player.
"I think the option of being prepared is having Option A, B and C. So, I guess we'll prepare D the rest of the day," Boucher said Saturday. "We have to prepare for different scenarios because they are really different scenarios that are possible. It's not clear cut at all."
Boucher said one of the players was feeling better than the other in terms of his spirits, although he wouldn't elaborate.
"One better than the other one, but pretty good," Boucher said.
If Kubina is unable to play, look for Randy Jones to see his first action of the playoffs. He has not played since early March with an ankle injury.
"We'll see tomorrow. I haven't decided yet. If Kubina can't go, Jones will be coming in. He's ready to go. He knows exactly what to do. He was playing against some top lines before he got injured," Boucher said.
It's not clear who would take Gagne's place in the lineup if the veteran winger is unable to go.
Meanwhile, Washington defenseman John Carlson, who did not play in the third period of Game 1, did not skate Saturday during the team's optional practice.
But coach Bruce Boudreau was hopeful that Carlson would be able to return to action Sunday.
"I think [there's a] pretty good chance that he'll play tomorrow. But I'm not 100 percent sure," Boudreau said.
Carlson did play one shift in the third period of the Capitals' 4-2 loss to Tampa but was too sore to continue.
"Yesterday he was sore. Because if we could have used him we would have used him," Boudreau said.
Defenseman Karl Alzner was likewise cautiously optimistic that Carlson would return.
"It's tough to say. I mean I didn't talk to him a whole lot, I just saw him getting treatment, that's about it. I think that most guys are optimistic about him," Alzner said.
The effect of Carlson's absence was felt in a number of different areas including the amount of ice time Mike Green had to log.
"The challenge is quite frankly, when you're down a goal you need his offense. I don't think it's any secret when you look at our team, Mike Green and John Carlson are our offensive defensemen, and the other guys are the stay at home defenders. When you look at Mike Green's minutes being 27 minutes, it's too high. He had a great series against New York and he's playing 18, 19, 20 minutes. Those are the minutes we have to get back to," Boudreau explained.
Scott Burnside cover the NHL for ESPN.com.