McKinstry has fallen off a cliff. At the end of May he had an OPS of .832, led the team with 10 steals, and was a capable, versatile defender. Maybe the best player on the team. And since May 31, his OPS numbers for June, July and August are .485, .610, and .530 and he's getting plenty of playing time. And he's 29 next year.
At the start of the year I said to myself "I like Vierling and McKinstry better than Willi and Harold" because those were the roles I saw for them. I still think that Vierling will survive, he's a RH who can play third or the outfield but he isn't going to start at either. As for McKinstry he could stick around but only because he is LH at this point, and you can't carry both him and Maton.