PHILADELPHIA — When the Phillies decided last week to stop using a conventional No. 5 starter in favor of Johnny Bullpen, president of baseball operations Dave Dombrowski defended the move by noting that “three of the best teams in baseball do it all the time.”

Somehow, though, it works much better for the Tampa Bay Rays. Go figure.

After deploying a nine-reliever parade to eke out a 10-inning win in Miami last weekend, the Phillies went bullpenning again Friday night. This time, rookie lefty Bailey Falter yielded three runs in the second inning, too much for a snoozing offense to overcome in an eventual 11-2 humiliation by the Colorado Rockies at Citizens Bank Park.

The Phillies have dropped four games in a row, including back-to-back defeats to the Rockies, who are 20-50 on the road. You could call it inconceivable, but the Phillies already achieved that distinction by getting swept last month by the league-worst Arizona Diamondbacks.

With the Atlanta Braves winning at home against the Miami Marlins, the Phillies slipped to 4 1/2 games out of first place with 21 remaining. If the Braves go 11-11 the rest of the way, the Phillies would have to finish 15-6 just to tie them. That’s a tall order for a 71-70 team that hasn’t been more than six games over .500 all season.

You can’t win if you don’t score, and the Phillies were blanked for eight innings by Rockies starter Germán Márquez and two relievers. Didi Gregorius went deep in the ninth inning — and took a turn with the “homer hat” despite a double-digit deficit at the time — to stave off a second shutout this week and ninth this season.

If it wasn’t evident already, it is now: When Bryce Harper doesn’t carry them, the Phillies don’t stand much chance, no matter if they have Zack Wheeler or Sam Coonrod on the mound in the first inning.

But for a team that is desperate to pile up wins, a bullpen game every five days isn’t ideal. It’s a copycat league, but if the Phillies are being honest, they aren’t doing this because they want to be like the Rays, Los Angeles Dodgers, or San Francisco Giants. They are doing it because they’ve run out of reliable starting pitching.

Zach Eflin is out for the season after knee surgery. Matt Moore has a 6.55 ERA as a starter. Vince Velasquez, whose ERA as a starter is 5.90, has been recovering from a blister on his right middle finger for six weeks. Chase Anderson isn’t in the organization anymore, getting designated for assignment a few weeks ago.

That’s how the Phillies ended up piecing together nine innings from Coonrod, Falter, Cam Bedrosian, Moore, Ramón Rosso, Enyel De Los Santos, and J.D. Hammer.