LOS ANGELES -- Lower back pain finally subsided enough for Thomas Stripling's oft-delayed bullpen session on Friday, but manager Dave Roberts wasn't sure of Stripling's next step.

The acquisition of Ryan Madson hours earlier, however, provides the Dodgers with an added option, as Stripling's slow recovery has had a ripple effect through a bullpen shaken by the uncertainty over Kenley Jansen after his latest irregular heartbeat episode, John Axford's broken leg and the transition of Kenta Maeda from starter to reliever.

• Dodgers acquire reliever Madson from Nats

Roberts said Madson's arrival might lessen the need for Stripling to throw multiple innings and hasten his return. Stripling was so effective out of the bullpen in April that he was given a spot-start when the rotation was besieged by injuries, and he capitalized on the opportunity to become an All-Star. Stripling was injured just as he was about to be sent to the bullpen by the return of Hyun-Jin Ryu to the rotation.

Injury updates: Axford, Urias, Utley
• Axford has resumed playing catch in Arizona and Roberts said the club expects him back at some point in September. Axford, acquired a month ago to essentially fill the role that Madson now has, had a line drive break his leg in his third Dodgers appearance.

• Julio Urias was scheduled to pitch in a rehab appearance for Triple-A Oklahoma City on Friday night. He's still trying to return from last year's shoulder surgery.

• With the roster expanding on Saturday, the Dodgers are expected to activate infielder Chase Utley off the disabled list.

Jarrin joining Ring of Honor
Dodger Hall of Fame broadcaster Jaime Jarrin will become the 12th inductee into the Dodger Stadium Ring of Honor during a pregame ceremony on Sept. 21. Jarrin will join Pee Wee Reese, Tommy Lasorda, Duke Snider, Jim Gilliam, Don Sutton, Walter Alston, Sandy Koufax, Roy Campanella, Jackie Robinson, Don Drysdale and Vin Scully in having his name permanently affixed to Dodger Stadium.

"The Ring of Honor is something that I never dreamed about, and I'd like to thank the Dodgers from the bottom of my heart." Said Jarrin. "To me, this honor is equal to being inducted into the Hall of Fame, and I'm humbled to be up there with Vin Scully and all the other Dodger greats. It's going to be a special night."

Jarrin, who is in his 60th year as a Dodgers broadcaster, was honored by the National Baseball Hall of Fame in 1998 as the recipient of the Ford C. Frick Award.