I don't quite get this tweet, and another article I saw referencing Mix is in trouble after drafting Harrison...Looks like if anyone is going to lose playing time to Harrison it's going to Mix if he doesn't step it up.
Reyna and PV have both come out and said that Harrison is a protypical winger. Mix is not a winger. I get it that Mix will have to fight for PT, but I think that has more to do with 1) the formation PV decides is best for the team and 2) fighting for PT with guys like Pirlo/Lampard/Poku/and dare I say TMac and AJ.
Maybe the selection of Harrison changes the formation that PV wants to deploy and could potentially force Mix to the bench, but I don't see Harrison as a direct threat to Mix's playing time.