Hideo Nomo, who pitched a pair of no-hitters and led a rush of Japanese players to the major leagues, is finished.

Nomo announced his retirement today, agent Don Nomura said. Once known for a deceptive delivery and a devastating forkball, the 39-year-old Nomo was released by the Kansas City Royals in late April.

Nomo's 123 wins are the most in the majors by a Japanese pitcher. He was the 1995 NL Rookie of the Year with the Los Angeles Dodgers and is one of only four pitchers to throw no-hitters in the AL and NL.

Out of the majors since 2005, he made a comeback this year and earned a spot in the Royals bullpen. But slowed by an injury late in spring training, Nomo had an 18.69 ERA in three relief appearances in which he gave up 10 hits, including three home runs, in 4 1-3 innings.

Kansas City general manager Dayton Moore said the Royals knew the odds were against Nomo when they signed him.

"But he still had the motivation to pitch, so we were more than willing to give him an opportunity," Moore said. "If he hadn't hurt his groin, who knows what he might have accomplished with us this year?"

A star in Japan before he signed with the Dodgers, Nomo made an immediate impact in the majors. He led the NL in strikeouts in 1995 and went 13-6 with a 2.54 ERA.

Nomo also created a wave of "Nomo-mania" wherever he pitched. Many fans were curious to see his "tornado" windup, in which he paused with his arms overhead and then twisted his body before throwing.

Opposing hitters weren't so eager to see him. Nomo's forkball took a wicked dip, similar to a split-fingered fastball. He was tough for catchers to handle, too — with balls often bouncing before the plate, he led the majors with 19 wild pitches as a rookie.

Nomo finished 123-109 with a 4.24 ERA with the Dodgers, New York Mets, Milwaukee, Detroit, Boston, Tampa Bay and Kansas City.

The right-hander's highlights were his two no-hitters.

In 1996 with the Dodgers, he pitched the first no-hitter in the history of Coors Field. He beat the Colorado Rockies at a time when pitchers routinely struggled at the mile-high ballpark.

Then In 2001, in his debut for the Red Sox, he pitched the first no-hitter at Camden Yards and beat Baltimore.

Nomo joined Cy Young, Jim Bunning and Nolan Ryan as the only pitchers to throw no-hiiters in both leagues.

When Nomo signed with the Dodgers, he became only the second Japanese player to reach the majors — Masanori Murakami pitched 54 games for San Francisco in the mid-1960s.

Following Nomo's success, many more Japanese players came to the majors. Hideki Irabu, Shigetoshi Hasegawa and Tomo Ohka were among those who quickly followed, with Ichiro Suzuki, Kazuhiro Sasaki and Hideki Matsui arriving later.

"He pioneered the Japanese players' transition to the United States," Moore said. "He was one of the dominant pitchers of his era."

AP Sports Writer Doug Tucker contributed to this report.