Consider this a 3rd endorsement for Mythrol's comment
I was all in favour of firing Gentry back when Demps got ousted, but a lot of people at the time argued that we should keep him just to maintain some degree of continuity through this year. I disagreed, but at the same time, I could see that argument: not stirring the pot
too much in a single Summer.
If you were going to fire him, then was the time. If you've left it this long (which we have) it's too late. Just leave it for this year and if he doesn't show the requisite improvements as the roster gets healthier, then get ready to cut him loose next summer.