Heading into training camp the Lightning roster held only a few vacancy signs for forwards.

Might three spots actually be taken by one line?

During the past two seasons the line of Ondrej Palat Tyler Johnson and Richard Panik helped carry the Lightning’s affiliate in the American Hockey League to consecutive Calder Cup championship appearances including a win in 2012.

That success led to all three receiving their first NHL experience last season with all three scoring their first goals.

The question now: Can the trio continue the chemistry and remain successful in the NHL?

“They play well together they understand one another they are good defensively so it just seems like kind of a simple transition here’’ Lightning general manager Steve Yzerman said. “They are all good players and (coach Jon Cooper) will ultimately decide where guys play but we know we have three guys who have good chemistry and work well at both ends of the rink. I think they will do that at the NHL level as well.’’

Last season Johnson was the MVP of the AHL after leading the league with 37 goals while Palat was the top scorer in the playoffs with 26 points in 18 games. Panik despite a 25-game call-up to the Lightning finished third on the AHL Syracuse Crunch with 22 goals in 55 games.

The three comprise one unit despite coming from different backgrounds. Panik was a skilled second-round pick in 2009 Palat an over-age late-round pick in 2011 and Johnson an undrafted free agent from Spokane Wash. For whatever reason the three just work well together.