PHILADELPHIA >> Help is not on the way after all.

The Dodgers were planning to give their beleaguered starting rotation a boost by activating left-hander Julio Urias from the injured list on Sunday. But Dodgers manager Dave Roberts said Urias has experienced renewed discomfort in his injured left hamstring and is not ready to rejoin the rotation.

“Julio is not going to pitch Sunday,” Roberts said before Friday’s game. “He threw a ’pen the other day (Thursday) in Cincinnati, about 20 pitches. He got through it, wasn’t overly confident in where that hamstring was at to take on a start. So we all decided to put a pin in it, go back to tempering back a little bit and not put a date on when he’s going to return. But hopefully it’s going to be sooner than later.”

Urias threw a live batting practice session on Tuesday and “felt okay” afterward, according to Roberts. But the hamstring tightened up on him during his bullpen session Thursday. Urias will continue throwing on flat ground to keep his arm active. But he won’t try throwing off a mound again until “I would assume some time next week,” Roberts said.

Urias has not pitched since a three-inning outing in St. Louis on May 18. Because of the extended time it has taken Urias to recover, Roberts said a minor-league injury rehabilitation assignment is likely before he rejoins the Dodgers.

Roberts said the Dodgers’ staff is still discussing how to handle Sunday’s game. Right-hander Gavin Stone was scheduled to start Friday for Triple-A Oklahoma City and Roberts said he was not a candidate to rejoin the rotation at this point.

Sunday will very likely be a “bullpen game” with a pitcher expected to join the Dodgers in Philadelphia and be placed on the taxi squad until then. Right-handers Andre Jackson and Matt Andriese would be the leading candidates to make the trip from OKC. Jackson started Thursday but threw just 10 pitches in his one inning. A former major leaguer who hasn’t pitched in the majors since 2021, Andriese is 4-2 with a 4.45 ERA in 11 starts for OKC. He would have to be added to the Dodgers’ 40-man roster.

After Sunday, however, the Dodgers have three off days in the next 11 and four in the next 15. That could allow them to go with a rotation of Clayton Kershaw, Tony Gonsolin, Bobby Miller and Michael Grove while waiting for Urias’ return.

“There’s a potential to work around it, given the upcoming off days ... depending on how this weekend goes, if guys need extra rest and all that stuff,” Roberts said. “But, yeah, given the off days, I think we potentially could manage it.”

Air quality

Smoke from Canadian wildfires has blanketed the East Coast this week, resulting in unhealthy air quality and the postponement of some MLB games, including one in Philadelphia on Wednesday.

Hazy conditions continued Friday but the air quality had improved in the area. Nonetheless, the Dodgers did not take batting practice on the field before Friday’s game at Citizens Bank Park.

“The main thing we did today was we kept our guys off the field,” Roberts said. “If we can keep them out of here as long as we can, as much as we can, it will probably be beneficial.

“Today seems better than it was yesterday so we’re hopeful that it will continue to dissipate.”

An air quality alert for the Philadelphia area was scheduled to expire at midnight Friday.

Farm moves

The Dodgers signed a pair of former major leaguers to minor-league contracts this week — former Angels outfielder Kole Calhoun and former Cubs left-hander Mike Montgomery.

Calhoun spent the past 11 seasons in the big leagues, the first eight with the Angels. But he was released by the Seattle Mariners at the end of spring training this year and again by the New York Yankees after hitting .281 in 23 games at Triple-A. Calhoun joined OKC this week and started 3 for 13.