Tommy John surgery.

Right-hander Blake Treinen pitched just eight innings before going on the IL with a forearm injury. He at least is expected back soon after the All-Star break. He pitched an inning for Triple-A Oklahoma City on Wednesday and will continue his minor league injury-rehabilitation assignment today.

The absence of that trio has left the Dodgers’ bullpen leaning to the left with Tanner Scott, Jack Dreyer, Anthony Banda and Alex Vesia.

“Yeah, when you’re losing three of your top relievers at any given time, certainly at the same time, it’s a hit,” Roberts said. “But it’s a good opportunity for other guys.”

Those “other guys” for now are Kirby Yates, Lou Trivino, Will Klein and Ben Casparius, who will be “shortened up” into a relief role after a brief run as a starter. Yates has the best resume of that group but has been vulnerable against left-handed batters this season — they have 11 extra-base hits (eight doubles and three home runs) and a .937 OPS against him this year.

“I think, obviously, Kirby is going to be better versus left. Hasn’t been great versus left so far this year,” Roberts said. “Trivino is a guy that we’re going to use. I think Klein is a neutral guy but using him in those spots, too. Yeah, we’re certainly heavy on the left-handed relievers for sure.

“We don’t have that righty killer. We’re going to have to match guys up.”

SNELL REHAB

Out since April 2 with a shoulder injury, left-hander Blake Snell began his rehab assignment on Thursday night with Class-A Rancho Cucamonga by pitching two shutout innings. He allowed one hit, struck out four and threw 31 pitches, touching 97 mph with his fastball.

With the minor leagues taking a break next week, Snell will pitch at the Dodgers’ training complex in Arizona on Tuesday, stretching out to three innings. He will need at least one more rehab start after the All-Star break before he could rejoin the Dodgers’ rotation.

MUNCY STATUS

A week after suffering a bone bruise in his left knee, Roberts said third baseman Max Muncy is “trending really well” in his recovery.

“Brandon McDaniel, one of our coaches, was at home yesterday and he talked to him,” Roberts said. “(Muncy) is already on the bike, his spirits are up, he’s moving around. I don’t know the timeline but just encouraged he’s making some good progress.”

Muncy is expected to be out at least six to eight weeks with the injury.

WAIVER CLAIM

The Dodgers claimed right-hander Nick Nastrini off waivers from the Miami Marlins.

Nastrini was the Dodgers’ fourth-round draft pick out of UCLA in 2021 and was part of the trade package that brought Lance Lynn and Joe Kelly from the Chicago White Sox in July 2023. Nastrini made the majors with the White Sox last year and went 0-7 with a 7.07 ERA in nine appearances (eight starts). Waived by the White Sox on July 1, he was claimed by the Marlins.

Nastrini will join OKC.

To clear a 40-man roster spot for Nastrini, the Dodgers designated right-hander Noah Davis for assignment.