Yermin Mercedes is in uniform for the Triple-A affiliate of the Chicago White Sox on Thursday, a day after hinting at retirement in an Instagram post.
Mercedes, who exploded onto the scene in April before struggling and being demoted at the beginning of this month, offered an apology for undisclosed acts of "immaturity" and said he may retire Wednesday.
"I want to apologize to all those who I inadvertently offended as a consequence of my immaturity, like members of the radio, television and press. To all the team's members who I was involved with, I'm sorry for failing as a human being and for not accepting some of their decisions. I'm stepping aside from baseball indefinitely."
Mercedes has since deleted the original post and said in another Thursday he will "never give up" on attempting to live out his MLB dream.
White Sox manager Tony La Russa said he planned on reaching out to Mercedes after hearing of his frustration.
"I understand you're in Triple-A, away from the big leagues, you can get emotional," La Russa told reporters Wednesday. "Don't know more than that. Will reach out to him. Could be just a little frustrated. I'll try to explain to him that he has a big league future."
Mercedes hit .415 with five home runs and 16 RBI in the month of April, emerging as a potential Rookie of the Year candidate, before his struggles led to him being sent down to Triple-A Charlotte.
La Russa had criticized Mercedes for ignoring a take sign and swinging at a 3-0 pitch for a home run in a blowout victory over the Oakland Athletics in May and benched him later that month for showing up late to the ballpark.