Rios (hand) will begin a rehab assignment at Triple-A Omaha on Sunday, Matthew DeFranks of FOX Sports Kansas City reports. Rios has been out since mid-April with the left hand fracture, so he may need a full week of rehab games before the Royals feel comfortable activating him. Upon his return from the DL, Rios should easily claim regular duties in right field over the light-hitting platoon of Paulo Orlando and Jarrod Dyson.