Rios signed a minor-league deal with the Reds on Tuesday, Charlie Goldsmith of The Cincinnati Enquirer reports.
Rios cleared waivers Saturday and elected to become a free agent, Charlie Goldsmith of The Cincinnati Enquirer reports.
The Reds designated Rios for assignment Friday.
Rios started at first base and went 0-for-3 in Monday's 6-0 win over Colorado.
The Reds selected Rios' contract from Triple-A Louisville on Friday, Charlie Goldsmith of The Cincinnati Enquirer reports.
Rios was outrighted to Triple-A Iowa on Sunday, Meghan Montemurro of the Chicago Tribune reports.
The Cubs reinstated Rios (groin) off the 10-day injured list Saturday and optioned him to Triple-A Iowa, Taylor McGregor of Marquee Sports Network reports.
Rios (groin) will head to Triple-A Iowa to begin a rehab assignment Wednesday.
Rios (groin) was cleared to resume baseball activities Tuesday, Jordan Bastian of MLB.com reports.
Rios landed on the 10-day injured list Wednesday (retroactive to Sunday) with a left groin strain.