"After about five minutes, I started throwing again and it felt better," Guardado said. "But it was still there. I guess I'll have to take little baby steps. That's all I can do. Believe me, if it was just a little achy, I'd probably still be throwing. It's the same thing."
Guardado, who was placed on the 15-day DL on Aug. 20 with forearm tendinitis, described the pain as "throbbing." He compared it to a pulled hamstring muscle.
The good news for Guardado is he still has eight days left until he's eligible to be activated. He will continue to undergo therapy and rehabilitation twice a day to get his forearm right.
The reliever wasn't worried he wouldn't be ready for Cincinnati's stretch run for the playoffs.
"I'm going to be back," Guardado proclaimed. "It's going to get better. As a competitor, I want to help the team out, right now."
In his rehabilitation assignment outing for Triple-A Louisville on Friday, reliever Gary Majewski allowed two unearned runs and one hit against Toledo. The right-hander, out since Aug. 7 with a tired shoulder, threw 16 pitches.
"If [Majewski] is throwing well and Guardado is throwing well, we've got two guys in September that will make a huge difference -- huge," Reds manager Jerry Narron said.
Penny for your thoughts?
With left-handed pitcher Noah Lowry on the mound for San Francisco, Narron featured a mostly right-handed lineup on Saturday. That meant Scott Hatteberg was out, while Rich Aurilia was at first base. Royce Clayton started at shortstop.
"Richie needs a day off too," Narron said. "It might be [Sunday]."
A day off is likely upcoming for left fielder Adam Dunn in Los Angeles on Tuesday, when Brad Penny is scheduled to start for the Dodgers. Dunn is 1-for-19 (.053) lifetime vs. Penny with 12 strikeouts.
Dunn has missed just two games out of 130 this season.
"I told Dunn he'd get one day off the rest of year and it would be when Penny pitched," Narron said. "I might change my mind, though. I really don't care how Dunner is against anybody. Any time he comes up, he can bump one."
Roster decisions ahead:
The Reds must set their postseason roster by Thursday. Narron and general manager Wayne Krivsky have had limited discussion about their plans.
"A little bit, but not much," Narron said.
With several players on the DL, the Reds will have some flexibility to add players after the deadline. They could also send a player to the Minors before Thursday and bring him back later.
"Any time you've got guys on the DL, it opens things up for the postseason," Narron said.
Kyle Lohse (1-0, 1.65 ERA) will start for the Reds against Giants right-hander Matt Cain (9-9, 4.53 ERA) in Sunday's series finale. First pitch is scheduled for 4:05 p.m. ET.