I think we are all falsely assuming Rendon would be in any Scherzer trade. He very well might not be.
I don't see how's he not. I don't see them wanting anything else. They clearly want to win next season and they will want pieces to do that and/or trade at the deadline. Rendon fills a pretty big need, which is a middle infield bat. Peralta probably won't be back and Iglesias OPS'd .654 with Detroit.
Harper and Strasburg are untouchable. There's no reason for them to trade Scherzer for a top flight pitcher, which eliminates Gio and JZ. Zimmerman would be blocked. Werth is costly and I don't see them wanting him. Austin Jackson is better than Span. None of our relievers (except for maybe Clippard) are worth a whole lot.
Which leaves us with Desmond, Rendon, and Clippard. Clippard alone isn't going to bring in Scherzer unless we pair him with our best prospects (Lucas, Goodwin, ect). That pretty much leaves Desmond and Rendon as the main trade bait, as they are very valuable and fit the Tigers' need.