How does that shown regression, it shows his point production has dropped. He was brought in to be a scoring center to replace Lecavalier which he did better than Lecavalier had been doing the past few seasons while being more responsible defensively. Johnson came along that year and is a better offensive player than Filppula so his role changed but he was still a key piece to the team. What has regressed is his shooting % and he's taking less shots than his first year here. His skills, physical ability and the rest of his game has remained where it was when he came and isn't showing signs of regressing.
His +/- actually improved last season from -14 to a -6, while Johnson went from a +33 to just +4, Stamkos has been roughly a ppg player his entire career yet is a +5 for it so it's not an indication of talent. Our entire teams offensive production took a huge hit last year, so everyone took a points hit the team wasn't nearly as strong last year. Filpulla is still a useful player who I wouldn't mind keeping around next year as he helps us win games, the guy has never missed the playoffs his entire career but if the right deal, which we haven't seen yet, comes along I'd move him, he's definitely not a buyout candidate.