Japanese right-hander Hideo Nomo has decided to call it quits after an illustrious career that included two no-hitters in the major leagues.

"I want to continue, but I don't think I can deliver a professional-level performance anymore. I believe many clubs think the same way," Nomo said Thursday.

"I knew I had to make some kind of decision. I knew I had to let my fans know," Nomo said.

No club has tried to acquire the 39-year-old's services since he was released by the Kansas City Royals in late April.