Mercedes in Triple-A lineup day after stepping away from baseball

Yermin Mercedes was in uniform for the Charlotte Knights - Triple-A affiliate of the Chicago White Sox - just one day after announcing he was stepping away from baseball, according to LaMond Pope of the Chicago Tribune.

The 28-year-old appeared to announce in an Instagram post on Wednesday that he was taking some time away from the game. The Knights removed him from their game for a pinch-hitter earlier in the evening.

Mercedes was named AL Rookie of the Month for April thanks to a torrid start to the season with the White Sox, but he was demoted to the minors in early July.

The rookie made headlines in May when White Sox manager Tony La Russa criticized him for swinging - and homering - at a 3-0 pitch while Chicago had a sizeable lead.

The White Sox said they didn't receive any official notification from Mercedes regarding his future plans.

La Russa suggested the slugger might have simply been frustrated about being in the minor leagues and said he would reach out to Mercedes to get him back on track.

"Kind of understand; you're in Triple-A, had a taste of the big leagues, and you can get emotional," La Russa said. "I'll reach out to him. It could be just a little frustration. I'll explain to him that he has a big-league future."

Mercedes has hit .271/.328/.404 with seven homers and 37 RBIs over 68 contests with the White Sox this year, though he did most of his damage early in the season.

A catcher by trade, Mercedes has appeared primarily as a designated hitter in the big leagues.