38 days left. While our current manager might make this list in the future, he's not there today. Let's go.
5. Keith Brown (0.5 WAR)
Brown pitched for the Reds from '88 to '92, wearing the number for the first 3 years of his tenure. He pitched mostly in relief, but compiled a respectable 3.40 ERA. He ended up playing in the minors for a few more years, ending in the Marlins organization.
4. John Tsitouris (2.7 WAR)
Tsitouris was a starter for the Reds through the 60s, from 1962 to 1968. His best year was 1963, where he went 12-8 with a 3.18 ERA, but other than that, was pretty unspectacular.
3. Bruce Berenyi (5.7 WAR)
Berenyi had the extreme misfortune of pitching for the Reds in the early 80s, from 1980 to 1984. Despite leading the league in losses in '82, he was a Rookie of the Year candidate in his first full season, and turned in 5 respectable years in the rotation.
2. Pete Harnisch (9.0 WAR)
Harnisch pitched for the Reds in the twilight of his career, but was still a pretty effective pitcher. He played for the Reds from 1998 to 2001, including a stellar 1999 campaign where he won 16 games.
1. Gary Majewski (-1.9 WAR)
Just kidding. Got to keep you on your toes.
1. Gary Nolan (26.3 WAR)
No-brainer alert. Rookie of the Year finalist, check. All-Star, check. Two World Series rings, check. Nolan pitched for the Reds from 1967 to 1977, when he broke in as a 18-year-old. He went 14-8 in his debut season, and impressively threw 5 shutouts. His best year was probably 1972 though, where he went 15-5 with a 1.99 ERA in 25 starts. His career was cut short by injury, but no Red did more with a #38 on his back than Gary Nolan did.