Doosan Bears infielder Jorge Cantu apologized and said he’s against racism after retweeting an offensive post which suggested Koreans look alike.

The former Major League Baseball player, who arrived in South Korea this season, called the tweet a “terrible mistake.”

Some angry fans had called for him to be sacked.

Cantu retweeted the message, titled “Desafio” or “Challenge” in Portuguese, which had a photo of Korean schoolchildren with one person’s face photoshopped onto different bodies.

It contained challenges such as “Find twin brothers” and “Find twin sisters.” Cantu, 32, posted it on Monday and removed it the next morning.

“From the bottom of my heart, my sincere apologies of this terrible mistake. I’m so against racism and discrimination,” the first baseman said on Twitter.

Cantu and his club, based in southern Seoul, also moved to calm fans by offering a formal apology at a news conference this week.

Cantu, who last played in the major leagues in 2011, has a batting average of .296 in 36 games this season with 11 homers, a performance which made him a hit with fans.

South Korean clubs have 28 foreign players. (AFP)