If you're talking about centers it's literally just Tavares or Duchene in free agency. Sam Bennett obviously, but I think that's largely a lateral move, and when you consider 7x10 for Bennett or 7x7 for Rossi, I think it's an overall downgrade.
The other problem is I don't see many high quality wingers available either. I don't think any of Marner, Granlund or Kane sign here, and I don't like Ehlers as much as some people do.
So it's not just centers imo, the path to improving the team in free agency just isn't really there unless it's something completely unexpected. That's why I kinda feel like his center help is gonna be Christian Dvorak, but even still, that's a massive downgrade, which means you need to get a 1 for 1 like Peterka in a Rossi trade.
My conclusion is that I think it's going to be very hard to improve the team next year if you trade Rossi. Rossi is our most realistic best chance at being a better team next year and in the near future.