Believe it or not, there's more than one entry to this list.
2. Ben Weber (-0.2 WAR)
Goodness gracious, how bad was Ben Weber as a Red? He was actually one year removed from a 4-year stint with Anaheim where he had an ERA around 3, and the Reds took him on as a low-risk, high-reward guy. Well, so much for that reward. Weber pitched to the tune of a 8.03 ERA in 10 appearances and that was all she wrote for Cincinnati (and for his career).
1. Mariano Duncan (0.5 WAR with #77, 2.1 total)
I'm sure most Reds fans will remember him fondly for wearing #7, but of the guys to wear #77, he's the most memorable one. Most will remember him for his main stint with the Reds on the 1990 team, but some may remember that the Reds brought him back in August of '95 for their playoff run. Darren Lewis was already wearing Duncan's old #7 at that time, so he doubled it up and the rest was history.
Duncan went on to hit .290/.329/.478 in 29 games off the bench for the Reds that year, including 2 hits in the NLDS against LA.
77 days left until Opening Day.