They just gotta keep playing .500 ball until Memorial Day, when the Braves and Mets loom. And that's exactly how long it will probably take Bryce and Ranger to truly contribute. They got a little fat on the weaker schedule and home games showed they can beat anyone any time as long as the 1-2 guys are on the mound (or with great pitching from Strahm or Walker when they have in fact provided it). Walker is a concern though; he's specifically not supposed to be Kyle Gibson 2.0.
Phillies were actually 17-20 last year starting on the night Bryce came back from his injury August 26. He whacked the ball his first week back and then had a .615 OPS (and astoundingly bad 42 OPS+ in September/October). And this is spring training for him, not just on the job rehab. But it all worked out last year.