F Nikita Kucherov played in the first period against the Panthers, but he did not return for the second.
Midway through the second, the Lightning ruled him out for the rest of the game with a lower-body injury.
Lightning coach Jon Cooper did not want to speculate on specifics but said he does not think it is long-term.
“It is the preseason, so precautions are No. 1, paramount for us,” Cooper said.
Kucherov scored 39 goals and added 61 assists last season. His 100 points were third-best in the NHL.
F Mathieu Joseph replaced Kucherov on the line with Brayden Point and Ondrej Palat.
Forward Tyler Johnson already missed the game because of an upper-body injury that Cooper expects will keep him out of the preseason.
GM Julien BriseBois said the Lightning are optimistic that Johnson will be ready for the regular season, but it is not guaranteed.
If Kucherov also misses time, the Lightning would open the season without two former all-stars.
Lightning first of many matchups
In case the Panthers and Lightning don't already know each other well, they will two weeks from now.
In the first two periods, the Lightning went on the power play three times while the Panthers had four power-play opportunities. Of all seven chances, F Adam Erne was the only player who capitalized. He scored off a Mathieu Joseph feed to the slot in the second period. F Alex Killorn later added to the Lightning's lead. F J.T. Miller picked up the assist on both goals.
Then, the Panthers scored three unanswered goals in the third, one of which was a short-handed goal from D Aaron Ekblad.
Cooper philosophy on AHL vs NHL
Cooper added that the competition in the AHL is very similar to the NHL.