Plus, bullpen sessions Friday for Bobby Miller and Clayton Kershaw

LOS ANGELES — Jason Heyward is back in the swing of things, literally, as he works his way back from lower back tightness that has sidelined him for the last five weeks.

Heyward swung a bat on Friday at Dodger Stadium ahead of the Dodgers’ series opener against the Braves, and also shagged fly balls in the outfield during batting practice, among other baseball activities.

“I saw him running earlier, full speed, pain free. He’ll be taking batting practice soon on the field, I would assume this week for sure.

After that will be a simulated game at some point in time,” manager Dave Roberts said. “He’s taking a couple of big steps, as far as being pain free and how his body is moving.”

Heyward last played in a game on March 30, and he’s been on the injured list since April 3. At first the lower back tightness was considered a short-term absence, but after he progressed slower than expected, the club called up Andy Pages to play every day, switching between right and center field.

Pages starts in right field on Friday night against Atlanta, his 15th straight start, and is hitting .291/.317/.545 with three home runs, five doubles, and a 141 OPS+.

It’s been nearly seven years since Heyward has played in a minor league game, and in between has completed six different injured list stints, all with the Cubs, without playing any rehab games.

But considering the time already missed, Roberts said Heyward would need a rehab assignment before returning, potentially three or four games, depending on how he’s feeling.

Back-to-back to LA

After Blake Treinen pitched Wednesday and Thursday for Triple-A Oklahoma City, his first back-to-back outing of his five-game rehab assignment, the veteran right-hander is going to join the Dodgers this weekend, potentially as soon as Friday night, at least in person.

Roberts stopped short of saying that Treinen would be activated during this homestand, which runs through Wednesday.

Preview the Dodgers’ next game.

“Blake had a good one yesterday. We’re going to give him a couple of days [off],” Roberts said. “My hope is that was the last [rehab game] he needed.

I think we’ll find that out once we talk to the trainers and Blake.”

Whenever Treinen gets activated from the injured list, his next game will be his first in the majors since Game 2 of the 2022 NLDS.

Bobby Miller threw off a mound on Friday, his first time doing so since landing on the injured list on April 13 with right shoulder inflammation.

“I’m not sure when his next ‘pen is,” Roberts said. “Once he starts facing hitters, I think it’ll ramp up quicker.”

Miller last pitched in a game on April 10.

Clayton Kershaw played catch on the field with Walker Buehler on Friday, which was a welcome site for all. Buehler will start for the Dodgers on Monday against the Marlins, and threw a bullpen session on Friday in anticipation of that start.

Kershaw also threw a bullpen session, his first since shoulder surgery six months ago to the day. Roberts said Kershaw made 15 pitches, and that he came out of it well.