Beezer, 5 seasons, nope.
Mellanby, 7.5 seasons, nope.
Svehla, 7 seasons, nope.
If management wants to acknowledge these players (+ a few others, Laus, Bure, Jovo, etc.), they can hold a tribute night like the Flyers have done this season to Timonen, Gagne and Briere.
Of the current Panthers, Kuli would be my darkhorse. Note: not saying that there aren't others that are worthy, just that he's already in his 7th season with the team (still ways to go to 15 though), DT stuck with him through the difficult years, we have the money to pay him in 2017 and the team is trending upwards. Obviously guys like Ekblad and Barkov are the obvious choices, but Kuli will reach the criteria faster if he remains with the team for another 7-8 years.