Dodgers rookie pitcher Walker Buehler still dealing with sore ribcage

The Dodgers postponed a bullpen session for rookie pitcher Walker Buehler, who is recovering from a microfracture in his ribcage. Buehler was expected to throw off a mound Saturday, but did not. Manager Dave Roberts indicated it was possible Buehler could complete this assignment Sunday.

“Walker is just still a little sore with the ribs when he plays catch,” Roberts said. “Walker, it’s more day to day, and figure out when we can get him [to throw] off the mound. Once we check that box, we’ll try to ramp him up.”

Buehler absorbed a line drive May 21. He made three starts before the symptoms of the microfracture started to affect his performance.

Buehler was put on the disabled list after his outing June 8. He had been dynamic as a starter this season, with a 2.63 earned-run average in nine starts.

The Dodgers do not necessarily need to rush Buehler back. The rotation has started to stabilize with Rich Hill, Kenta Maeda and Clayton Kershaw all activated this month. Kershaw on Saturday made only his second start since May 1 and pitched three innings.

Roberts was less optimistic about the condition of Hyun-Jin Ryu, who tore a groin muscle May 2. Ryu had been making progress, but has not been able to pitch off a mound, Roberts said. Roberts does not expect Ryu to pitch again until after the All-Star break.

“From what I understand, he’s back to just playing flat-ground catch,” Roberts said.

Chris Taylor still nursing hamstring

Chris Taylor sat out for the second game in a row because of a sore left hamstring. He is not expected to play Sunday, either. Taylor completed agility drills before the game. The team is hopeful he will not require a stint on the disabled list.

“As far as the D.L., we’re OK with not having to make that decision,” Roberts said.

With Taylor on the mend, Enrique Hernandez has started at shortstop.

Adam Liberatore is sent to minors

The Dodgers optioned reliever Adam Liberatore to triple-A Oklahoma City to make room for Kershaw’s return from the disabled list.

andy.mccullough@latimes.com

Twitter: @McCulloughTimes