Cincinnati hoped long reliever Victor Santos could make the start, until he was needed from the bullpen against the Cubs on Wednesday. Ditto for lefty Mike Gosling, who was used in relief Thursday at Chicago.
That left Ramirez.
Reds interim manager Pete Mackanin said the reports from Louisville manager Rick Sweet have been positive.
Ramirez was 3-3 with a 3.75 ERA, 18 walks and 36 strikeouts in 11 starts with Louisville this season. The right-hander didn't start pitching until returning from shoulder tendinitis on June 12. He made one relief appearance for the Reds on Aug. 1 against the Nationals and worked two scoreless innings.
"[Sweet] said in his last two outings [Ramirez] pitched well," Mackanin said. "His command was good. Everything was pretty good. He went into the sixth inning a couple of times. His last time, he had a real good showing in Washington."
In his previous start for Louisville, Ramirez allowed three earned runs and eight hits with no walks and five strikeouts over 5 1/3 innings.
"He's been up to 90 pitches, [Sweet] said," Mackanin said. "His pitch count is up to where he can give us some length."
Ramirez last started a game for the Reds at Philadelphia on Aug. 12, 2006, and made it only 1 1/3 innings partially because he was needed as a reliever in an extra-inning game the previous night.
Spoils for the spoilers:
The Reds are far back in the National League Central race but can still be a factor in the division's final outcome -- and a pesky problem for all remaining NL contenders.
Coming off taking two of three from the Cubs this week, Cincinnati entered Friday 32-33 against teams with .500 records or better. The Reds are only 20-35 against clubs with losing records.
"I never give the season up," Reds right fielder Ken Griffey Jr. said. "Until we're mathematically eliminated, you can't until you're done. You can still make it tough on other teams. If you get eliminated, there's no more satisfaction than helping someone else go home with you."
After Friday, the Reds have 20 more games against the top three NL Central clubs -- eight with Milwaukee, six with Chicago and six against the recently surging Cardinals.
Catcher David Ross, who suffered a concussion during a home plate collision in Sunday's game against the Padres, was cleared to begin light physical activity. Ross is on the 15-day disabled list.
He said it:
"That's twice what I'm making, jeez." -- Mackanin joking after hearing about Cubs pitcher Carlos Zambrano's new five-year, $91.5 million contract signed on Friday.
Ramirez will start against Brewers right hander Claudio Vargas (9-4, 4.87) Saturday at 7:05 p.m. ET.