PHILADELPHIA -- For a team that led the Majors in ERA each season from 2019-22 (and finished second in '17 and '18), the Dodgers are facing plenty of questions up and down their pitching staff in '23.

For now, they seem to have very few answers.

Los Angeles used an opener ahead of Michael Grove to put the righty in the best spot possible against the Phillies' lefty-heavy lineup on Friday night at Citizens Bank Park, but the result was more of the same. As for the backend, the Dodgers called on Caleb Ferguson in a tie game in the ninth inning, only to watch him serve up a walk-off homer in his third consecutive rocky outing.

Put it all together and the Dodgers came out of a 5-4 loss -- their third walk-off defeat in the past four days -- with a 4.52 team ERA this season, which ranks 22nd in the Majors.

"It's tough. It stings," manager Dave Roberts said. "A loss is a loss, but when you feel like you're in it, and you get walked off, that never feels good."

Entering behind opener Victor González, Grove -- who entered with an 8.14 ERA this season -- recorded only 12 outs while watching his season ERA increase to 8.28. He allowed four runs off seven hits and one walk over four innings.

Though Grove had been listed as the starter, Roberts instead pivoted to using an opener. The logic was simple: Grove has been hit considerably harder by left-handed hitters and the Phillies boast two powerful left-handers -- Kyle Schwarber and Bryce Harper -- within their first three batters.

Grove, pitching in his 13th MLB game, allowed a .315/.383/.583 slash line to lefties in his first 12 outings. That .967 OPS was more than 300 points higher than the .657 OPS he had allowed to righties. In the Minors last season, left-handers had an .885 OPS against Grove (he held righties to a .634 OPS).

Schwarber and Harper indeed got to Grove in the third, but it was right-handers Trea Turner and Nick Castellanos who delivered the final blows to Grove in the fifth.

"When I get out there, I've got to do my job," Grove said. "And I didn't do my job today."

That all came just hours after Roberts announced that Julio Urías -- sidelined since May 18 -- would not return from his strained left hamstring injury on Sunday, as the club had hoped. The Dodgers will likely be without Urías for at least a few more turns through the rotation.

So with Grove serving as one of only four healthy starters in the rotation, Los Angeles -- and Grove himself -- knows it needs more out of him.

"That's the expectation that I have for myself and they have for me," Grove said. "So a day like today, with all the pitches I threw and not being able to get a lot of the game eaten up, I have to do a better job."

Though the Dodgers faced a 4-1 deficit when Grove exited, they rallied to tie the game courtesy of back-to-back seventh-inning homers from Mookie Betts and Freddie Freeman.

With the game still deadlocked at 4 heading to the bottom of the ninth, Roberts turned to Ferguson -- opting to reserve Evan Phillips for a potential save situation in extras.

It never got there.

After making quick work of the first two batters, Ferguson left an 87.3 mph cutter over the heart of the plate. Schwarber laced a no-doubter into the right-field seats.

"One bad pitch to a really good hitter," Ferguson said. "Left it over the plate, that's what they do."

After putting up a 1.35 ERA and not allowing a home run in his first 23 appearances, Ferguson has allowed at least one run in each of his three June outings. He allowed his first home run of the year in Sunday's loss to the Yankees, then blew a save opportunity in Tuesday's loss to the Reds.

Ferguson has allowed six runs off three hits (two homers) and four walks over just two innings in his past three appearances.

"He's frustrated," said Roberts, who added that he had a quick chat with Ferguson immediately after Friday’s game just to pick him up. "You never want to get walked off, but that potential comes with pitching late in games."

And given the state of the current pitching staff, that’s something Ferguson will continue to do for the Dodgers.

“We need him. We need him, absolutely,” Roberts said. “ ... Looking at the construction of this 'pen, you have to use your players. I'm counting on him.”

With no rotation help on the horizon, Los Angeles will be counting on Grove, too.