Shohei Ohtani #17 of the Los Angeles Dodgers runs the bases in the seventh inning during the game against Miami Marlins at loanDepot park on September 19, 2024 in Miami, Florida. Chris Arjoon, Getty Images/AFP/FileTOKYO, Japan -- Baseball superstar Shohei Ohtani and his wife Mamiko Tanaka are expecting their first child, the World Series winner announced Sunday.

"Can't wait for the little rookie to join our family soon!", Ohtani wrote on Instagram, alongside a picture of baby shoes, a baby sleepsuit and his adored pet dog, named Decoy.

Ohtani was named the National League Most Valuable Player after a historic first season with the Los Angeles Dodgers in 2024 that saw him become the first player to score 50 home runs and steal 50 bases in a single Major League Baseball campaign.

READ: Japanese baseball fans celebrate Ohtani winning third MVP award

The 30-year-old capped it with his first World Series win as the Dodgers beat the New York Yankees 4-1.

Fans soon congratulated the pair.

"Thank you for this most delightful, biggest piece of news at the end of the year, after everything you've done throughout the year to keep Japan happy", one commented.

"I'm so thrilled for you two! ... Decoy is going to be such a great sibling", another wrote.

In February, Ohtani surprised fans by announcing that he had married Japanese basketball player Mamiko Tanaka.

READ: Dodgers' Ohtani reveals identity of wife after intense speculation

The Dodgers are scheduled to open their 2025 season with two games against the Chicago Cubs in Tokyo on March 18 and 19.

© Agence France-Presse