He is going to turn 35 before he plays a game on his next contract. If he puts up another dud in the playoffs, how can you justify brining him back? I'd pump the brakes for now.
Gourde, Granlund, Dvorak and Bennett are your next best C's, that "might" get to UFA.
Bennett is the only one you might argue about being equal of Tavares... If you could sign Bennett, and keep Tavares, it would make for a pretty deep team down the middle, but it would have to be affordable to do so. I have a hard time imagining where Florida doesn't extend him, as he's been an important piece for them...but there is the cap.
The cap is supposed to go up by $4.4 mil next year, and they've already extended Verhaeghe with an increase $2.833. So, barring trading away someone, they have approx $1.566 mil left in pay increases, to extend Bennett, Ekblad, both Boqvists, and Schmidt.
The max Florida can offer Bennett, if Ekblad extends at his current $7.5, would be $6 mil. I'm not saying Ekblad would accept that... but to sign Bennett, you probably have to go to $7-$7.5 mil, or he'd just take the $6 mil in Florida. I like Bennett, and his all around game, but he is prone to missing time, and is a career high 49 points, though he may eclipse that this year (26 points in 30 games) ... and be in line for a bigger payday as a UFA. (and if he does, someone is going to deeply regret that).