In the six seasons in which he played at least 60 games, he's had 20, 27, 15, 19, 14, and 15 goals, which averages out to 18-ish goals per full-ish season played. You can do worse as a fourth line player. If he sets his sites on the front of the net, instead of looking for the open-ice hit, he might even improve his offensive numbers. He doesn't have to be a torpedo to be effective. He's built like a fire hydrant and is basically impossible to separate from the puck.
He's probably too slow and too stupid to be a good defensive player, but if Tippett can get him to buy into being a puck cycling extraordinaire, I don't see why he can't carve out a niche as a solid forechecker/net crasher ala Joel Ward. Ward doesn't lay people out or take penalties. He just keeps his feet moving and never loses the puck. He's a valuable NHL player. Anyone remember Mike Grier? Same way (of course he was great defensively, too, and actually had wheels for a big guy). You can be useful in the offensive zone if your only skills are being powerful, determined, and willing to go hard to the net.
He just needs a shift in identity. He needs to realign his goals from game to game. His focus can no longer be "provide a spark". When watching video with Steve Peters and John Anderson they should talk about how many minutes and seconds he was able to maintain possession of the puck in the offensive zone. They should focus on how few penalties he's able to take, and how well he's able to screen the goalie and crash the net. How much time he manages to spend within three feet of the opposing crease. That kind of thing. Less Matt Cooke and more Tomas Holmstrom.