If you can move Pyatt, sure. If you demote him, he carries a cap hit of 625K. That plus Yogan's 800K get you almost to right back to Pyatt's salary.
Whether it's a minor cap gain or minor cap hit you need to do what's best for the team regardless, so if Yogan could replace Pyatt and actually be an improvement I think you have to do it regardless of whether or not you can move Pyatt but ideally you can get a pick out of him, or he gets claimed off waivers.
I actually think that can help a guy like Yogan. If he can play an effective game and replace Pyatt who's making twice as much, then it's a cap gain for the team.
With the cap, you do kind of have to keep a pipeline of younger, cheaper players coming in and I think that goes for bottom line players as well.
And you have a younger, hungrier and most probably faster player on your team in Yogan + the possibility of moving Pyatt somewhere else for another asset.
Using Pyatt as an example here is excellent. You have a 3rd-4th liner with a lot of history--some of it very sad but a hockey team shouldn't be in the business of anything but putting the best product possible on the ice. Pyatt did not do much offensively for us last year apart from the very beginning and the very end of the season. A bottom liner who gets his hits in--if you look at the stats anyway because few of them are memorable. He doesn't pk. I don't like bottom 6 forwards without some kind of specialty. He doesn't add much offense--he doesn't pk--he doesn't fight. What does he do? This is where a kid like Yogan can move in. Do the pk--have the occasional fight--knock in the odd goal. Make yourself useful.