Ankiel back in Kansas City for treatment

ATLANTA -- Royals center fielder Rick Ankiel has had a setback during his minor league rehab assignment and returned to Kansas City for treatment on his right quadriceps.

Royals manager Ned Yost said Ankiel, who has been on the 15-day disabled list since May 4, "tweaked his quad" at Triple-A Omaha this week. Ankiel went 2 for 5 with a double and a homer Monday and was hitting .278 in five games.

After signing a one-year, $3.25 million contract as a free agent, Ankiel has a .210 average in 19 games with the Royals. Kansas City went 5-11 with Ankiel in the lineup.

Yost indicated there is no timetable for the return of Ankiel, whose rehab assignment started June 8. The Royals had hoped the pitcher-turned-outfielder would be back in the lineup for this weekend's series against Atlanta.