LOS ANGELES -- When the Dodgers traded for left-hander Danny Duffy at the Trade Deadline, they knew sometime in September was the earliest they would see the left-hander take the mound in a big league game.

On Friday, Duffy was scheduled to throw a “big” bullpen session, one that would determine his availability for the rest of the season. Unfortunately for Duffy and the Dodgers, the veteran left-hander experienced left elbow pain during that bullpen session at Dodger Stadium.

Dodgers manager Dave Roberts said Duffy was able to start the bullpen session, but he shut it down before reaching his pitch limit. He’s unsure of the severity of the injury, but his season appears to be over.

“It doesn’t look good,” Roberts said. “Outside of any sort of miracle, for him to impact us this year, it’s going to be tough.”

Acquiring Duffy from the Royals didn’t come at a large cost for the Dodgers, as they’re scheduled to send a player to be named later to Kansas City based on Duffy’s performance in Los Angeles.

But losing Duffy does give the Dodgers one less veteran option for its postseason roster. The plan for the Dodgers was to have Duffy as a “two-inning monster” out of the bullpen, almost similar to what Julio Urías did last postseason.

Now, the future is uncertain for Duffy, who is an unrestricted free agent at the end of the season. He was having a solid season, posting a 2.51 ERA in 13 appearances (12 starts) this season.

Turner, Betts flip in the lineup

Trea Turner has been hitting leadoff since he made his debut with the Dodgers on Aug. 6. That’s where he’s hit for the majority of his career, helping him become one of the most dynamic players in the Majors.

But with the Dodgers in a current offensive funk, they’ve decided to mix things up. Mookie Betts, who has been the team’s leadoff hitter for most of the last two seasons, returned to the leadoff role on Sept. 9 against the Cardinals. That will be the plan for the foreseeable future.

The thinking behind the move is that Betts gets on base at a higher clip. In his time as the team’s leadoff hitter this season, Betts has a .379 on-base percentage. Since Aug. 6, Turner’s OBP at leadoff is .357.

Turner said he doesn’t “particularly care” where he hits in the order and doesn’t think there’s much of an adjustment.

“We felt like we’ve played pretty well, but we can play a little bit better,” Turner said of the lineup change. “Hopefully it’ll let us score more runs and win more ballgames.”