Right now the manager isn't the problem it's the badly ageing team he's been handed.
At the beginning of the season I thought the starting pitching would carry them through to the second wild card. Hard to see that happening now though with Estrada, Stroman and Biagini flopping.
Future looks brighter though with all those contracts due to come off over the next couple of years with the money, hopefully, that will release and young talent coming through, notably Vlad junior.
We know the manager isn't the problem, but many people want to use him as scapegoat. You can't fire the players, so you blame the manager. I believe in other sports like hockey, basketball and football, the coach plays a bigger role. Finding the right chemistry of the guys on the floor/ice, match ups, time management, etc. There's much less of that in baseball, but you still can't fire the players so manager is the one they point to.
Biagini has had some bad luck, but I think he's proven he's much valuable out of the pen. I think eventually Stroman and Sanchez will be fine. Stroman needs to learn he's not superman, and if he's hurt, shut it down. He does more harm than good to both himself and the team. Sanchez missed pretty much the whole season last year, and changed the way he pitches. I think the blister issue is still in his head and he's worried it will come back causing him to miss more time if he uses the same arsenal he did in the past. We've seen the best of Estrada. His change up just isn't fooling as many people anymore, and he doesn't much else so he has to keep throwing it, and hitters sit on it.