There isn't a firm plan in place, but Padres interim manager Pat Murphy said Morrow will likely begin a rehab assignment soon. Morrow began a rehab earlier this summer, but suffered a setback June 10 that resulted in him being temporarily shut down.
'We've been taking everything step-by-step this time," Morrow said. "They never really showed me a planned-out schedule. It was, 'Throw a [bullpen session], then schedule the next one.'"
Morrow called Saturday a positive step, and said everything went as planned. Murphy watched the simulated game and said he was encouraged by what he saw, for the most part.
"He threw the ball well considering he hasn't been out facing hitters in a long time," Murphy said. "I thought he competed well. He wasn't real, real sharp, but I think he feels ready for a rehab assignment."
Morrow was 2-0 with a 2.73 ERA in five starts before his injury.
• Tim Federowicz, who is recovering from right knee surgery, caught Morrow's simulated game and headed out for Class A Fort Wayne for a rehab stint. Federowicz hasn't played in the Majors this year, but is a .194 career hitter with five home runs in 247 big league at-bats.
• Will Middlebrooks was in Saturday's lineup starting at shortstop for the second time this season. Middlebrooks entered hitting .217 with nine home runs, and Murphy said this move could have future implications.
"We're looking at it as trying to give him a shot to play there," said Murphy. "He's played there a couple of times this year and done well, and the staff felt like that might be a nice improvement from a range-purpose. We'll watch it closely and see if it's something. He's got to get it kickstarted, too. He's got to start contributing more."
• Murphy said he plans to start his pitching rotation from the top, starting with James Shields, after the All-Star break.
Cody Stavenhagen is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.