Bruce Chen held the White Sox to one run over five innings in a win Tuesday.
Bruce Chen allowed two runs on eight hits over 5 1/3 innings of a no-decision against the Tigers on Sunday.
Royals activated LHP Bruce Chen from the 60-day disabled list.
Royals transferred LHP Bruce Chen from the 15-day disabled list to the 60-day disabled list.
Bruce Chen (back) is expected to need two more rehab starts before being activated from the disabled list.
Bruce Chen (back) will make a minor league rehab start Tuesday will Double-A Northwest Arkansas.
Bruce Chen (back) will be cleared for a rehab assignment if he gets through a bullpen session Sunday with no issues.
Bruce Chen (back) threw live batting practice on Friday.
Bruce Chen (back) felt "really good" during a 25-pitch simulated game Monday.
Bruce Chen (back) isn't close to beginning a rehab assignment.
Bruce Chen (back) hopes to throw a light bullpen session Wednesday.
Royals general manager Dayton Moore said Tuesday that the club is "unsure" about Bruce Chen's (back) timeline at this point.
Royals placed LHP Bruce Chen on the 15-day disabled list, retroactive to April 25, with a bulging disk in his back.
Royals manager Ned Yost said Thursday that he expects Bruce Chen (back) to be placed on the disabled list.