"I don't know how many throws, probably 75 throws. It felt really good," Marshall said. "From the first throw, the ball was smooth coming out of my hand. My shoulder felt really smooth. I didn't feel anything I was running into. I was very encouraged for day No. 1."
Before Marshall had his second surgery in two seasons, he went in expecting it to be season-ending -- and likely career-ending. That's because he was gearing up to have a torn capsule in his shoulder repaired. But a tear was not found, and surgeons only had to remove scar tissue that obscured the MRI results.
So instead of wondering if he could simply play catch with his kids again, Marshall got back to preparing to pitch again for the Reds -- possibly this season.
"Great day today," Reds manager Bryan Price said. "As we know, Sean Marshall is one of the better relief pitchers in baseball. [When he] ends up playing catch on the first day of July, it's a special moment for all of us in the organization.
"He looked normal. He looked like a normal guy out there playing. Coming off a shoulder surgery, it's remarkable to see. Ten minutes of throwing, it's incredible how amazed you can be by 10 minutes of a game of catch."
Shoulder injuries have limited Marshall to 31 games since the start of the 2013 season, but he has not pitched at all since he had surgery last June to repair a torn labrum. He also missed significant time with left shoulder tendinitis in '13.
Marshall, 32, led the Majors with 231 appearances from 2010-12. He is making $6.5 million this season in the final year of his contract.
There is no timetable for Marshall to return this season, but he's optimistic that it could happen.
"My endurance is great. My range of motion is good," Marshall said. "Those are a couple of things I was battling with coming out of the previous surgery. So far, everything is in a very positive direction, for sure.
"If I keep stepping in a positive direction, there's no doubt about it. I'd like to get back in the bullpen and be with my boys down there."
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.