Holliday and Castro should be back by the time we return from the All Star Break, maybe even during this series against Milwaukee. That'll be a nice little boost. But ultimately the bullpen, specifically Betances/Chapman, need to get back to pitching like studs for us to get back in the race.
The amount of blown saves and close games gone awry thanks to the bullpen over the past 30 day stretch has been pretty abysmal. The bullpen is a strength of the team and once (if) it returns to normal, I think we'll be in good shape.
Green/Warren/Betances/Chapman for the 6th-9th is pretty formidable (plus Clippard if he can turn it around). All we'd really need from guys like Pineda and CC are 5 innings of non-horrible pitching.