Popular former outfielder Tsuyoshi Shinjo, who has announced on social media that he wishes to resume playing professional baseball, officially unretired on Wednesday when he was listed as a free agent eligible to sign with any club.

The 47-year-old played for the Hanshin Tigers, New York Mets and San Francisco Giants before ostensibly finishing his career with the Hokkaido Nippon Ham Fighters in 2006.

As a retired player, Shinjo could only sign with his last team, the Fighters, but Nippon Ham released him instead, and the commissioner’s office changed his status to free agent.

In a video posted on his Instagram account earlier this month, Shinjo revealed his intent to play at the professional level again.

“I will begin training today so I can become a professional player one more time,” he said.

Known as “spaceman” for his sometimes off-the-wall pronouncements and “prince” because of his swagger, Shinjo debuted with the Hanshin Tigers as a shortstop but made his name as a speedy, strong-armed center fielder.

Shinjo spent three seasons in the majors from 2001 to 2003, and returned to NPB to play for the Fighters in 2004.

He abruptly retired at the end of the 2006 season, after contributing to Nippon Ham’s first Pacific League pennant since 1981 and helping the team win the Japan Series.