Phillies reliever José Alvarado throws a bullpen session as he looks to return from elbow injury

ATLANTA — After riding the high of a come-from-behind, extra-innings win on Wednesday, the Phillies received some more good news on Thursday. José Alvarado, who was placed on the 15-day injured list on May 10 with left elbow inflammation, threw his first normal bullpen session on Wednesday. Phillies manager Rob Thomson said it went well, and Alvarado will throw another bullpen on Saturday.

If that session goes well, Alvarado likely will throw batting practice next week in New York, when the Phillies are there to play the Mets. Thomson has said Alvarado will need to go on a rehab assignment, but he hasn’t specified where it will be or how many outings Alvarado will need.

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The Phillies’ bullpen has done a good job holding things down in Alvarado’s absence. From May 10-25, it has a 1.76 ERA, the second-lowest in baseball, and has cut down on its walk rate over that span, from 11.3% to 9.7%, and raised its strikeout rate from 25% to 28.7%.

Nevertheless, Alvarado’s arm is missed, especially in high-leverage spots. He was one of the most dominant relievers in the sport, if not the most dominant, when he was placed on the injured list. Through 14⅓ innings this season, Alvarado has a 0.63 ERA with no walks and 24 strikeouts.

Brandon Marsh was in the lineup for the second straight day on Thursday, after the center fielder was abruptly scratched from the lineup ahead of Tuesday’s game with right shoulder inflammation that later was described as back pain. There were concerns that the inflammation would affect Marsh’s swing, but Thomson said his swings looked good to him on Wednesday after some treatment with a chiropractor.

“We’ll monitor it because it was bothering him last year a little bit,” Thomson said. “It’s like a toothache, you just have to take care of it. Yesterday, the swing looked completely different. Just goes to show you — knock that thing out now, and all of a sudden he can stay through the ball, use the other field, he’s not trying to cheat or cut his swings off.”

Thomson said he hasn’t made a decision yet on whether Dylan Covey, who was claimed off waivers from the Dodgers and gave the Phillies five innings of one-run ball on Tuesday, will make his next start. He plans to announce more details Friday. ... Rafael Marchán (right wrist fracture) could start a rehab assignment as soon as Sunday. … Darick Hall (right thumb sprain) could start a rehab assignment early next week. Hall and Marchán’s rehab assignments will begin at single-A Clearwater.