The Reds selected Rios' contract from Triple-A Louisville on Friday, Charlie Goldsmith of The Cincinnati Enquirer reports.
Rios has been at Louisville all season, where he's put up an .826 OPS with 11 home runs over 50 contests. The 30-year-old is capable of handling the corner infield and corner outfield spots, but it seems unlikely he'll garner much playing time with Cincinnati.