The Reds activated third baseman Scott Rolen off the 15-day disabled list for the start of their weekend series against the St. Louis Cardinals.
The Reds optioned infielder Scott Valaika to Triple-A Louisville on Friday to open a spot.
The 36-year-old Rolen got two cortisone injections last month for a stiff left shoulder and neck. He went on the disabled list April 24, batting .217 with two homers and 12 RBIs.
Valaika batted .313 in eight games without a homer or RBI. He started four games at third base.