Forward Cory Conacher, who played in Games 3 and 4 of the first round against the New Jersey Devils, is another option.
"If [Erne's] ready to go, we have to make some decisions in regard to that," Cooper said. "But as I said, I'm not judging our playoffs in 48 hours."
The Lightning also could go with seven defensemen and add Andrej Sustr or Slater Koekkoek to the lineup. Neither has appeared in a game during the postseason or played much during the final weeks of the regular season. Sustr has been in the lineup six times since March 1, and Koekkoek has played three times during that span.
They do, however, have playoff experience. Sustr has five points (two goals, three assists) in 46 career postseason games. Koekkoek has one assist in 10 playoff games.
Whoever plays, Cooper remains confident the Lightning can rebound in Game 3.
"They've got 113 points (in the regular season) for a reason," Cooper said. "There's a really good group of guys there. They've got a ton of experience, and when their backs have been against the wall, they've shown a propensity to fight back. This is a tough one. We lost two at home and it's definitely not an ideal situation. But we're not done. It's not over."