Yermin Mercedes is back one day after appearing to retire from baseball.

The Chicago White Sox say Mercedes is in uniform and on the active roster for the triple-A Charlotte Knights Thursday in Durhan, N.C., against the Bulls.

Mercedes seemed to announce his retirement on Instagram on Wednesday. He posted an image of the words “it’s over.”

“First of all, I want to thank God for giving me life to the fans that without them I’m nothing,” he wrote. “I walked away from baseball for a while. God bless you. It’s over.”

Hall of Fame manager Tony La Russa said he had just heard about Mercedes’ decision to step away and planned to reach out to him. He said Mercedes has a “big league future.”

“You’re at Triple-A, you’ve tasted the big leagues, you can get emotional,” La Russa said. “But I don’t know more than that.”

The 28-year-old Mercedes sparked Chicago’s offence through the opening months of the season, batting .415 with five homers and 16 RBIs in 22 games in April. In May, Mercedes angered La Russa by homering on a 3-0 pitch in the ninth inning of a game the White Sox led 15-4.

“As you probably know, if you’re paying attention, several times he’s said how close we were,” La Russa said. “He knows I’m a supporter of his. So I’ll reach out to him and see what’s going on. It could be he’s just a little frustrated.”

For the season, Mercedes is hitting .271 with seven home runs and 37 RBI in 68 games. However, Mercedes has hit just two home runs since the end of April and has a batting average of .198 and an OPS of .536 over that span.