Koji Uehara is suffering from a strained right hamstring and has been told by doctors to refrain from pitching for a week, the Yomiuri Giants right-hander said on his official Web site Friday.

Uehara, who is expected to start on Opening Day for the sixth straight season in the home game against the Hiroshima Carp on April 1, skipped his scheduled start in a preseason game against the Chunichi Dragons in Shizuoka Prefecture on Friday.

"I felt a sharp pain in the lower half of my body during a bullpen session Wednesday," said Uehara.