The league has been getting faster, and Seabrook doesn't seem to have made any efforts to slim down, improve his speed, or keep up... THAT'S the problem people have with him. The fact that even his teammates joke about what he eats makes it worse.
Jagr did it in 2014-2015, when he realized he wasn't fast enough to keep up with the kids in Florida. He lost 23 pounds, and worked on getting FASTER. Seabrook could stand to lose 20 pounds. I know he's listed at 220 lbs, but, much like Byfuglien, I think that's wishful thinking. He's probably closer to 230, 235.... If he dropped just 10 pounds, it would make a HUGE difference on the ice, even if he didn't work on improving his skating at the same time.