GLENDALE, Ariz. -- Luis Robert, the No. 3 White Sox prospect and baseball's No. 28 prospect per MLB Pipeline, will begin the season on the disabled list, not in the outfield for one of the White Sox Class A farm clubs.
Robert has been diagnosed with a moderate Grade 2 left thumb ligament sprain. Robert suffered the injury while sliding into second base Wednesday on a stolen base. He remained in the game and hit a game-winning grand slam in the eighth inning in a 14-12 victory over the Reds.
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"The thumb will be immobilized for approximately the next six weeks," White Sox general manager Rick Hahn said Saturday. "He will ideally be able to return to game action in roughly 10 weeks.
"As a result, he's obviously done for Spring Training. We would expect him probably roughly in extended games in early May. Hopefully we can adjust that timetable for the better once the cast comes off, but at this time, we view it as six weeks in a cast and return to games in approximately 10.
"He sustained the injury prior to the grand slam, which is a pretty impressive pain tolerance by the young man, and also speaks to the speed of the potential recovery here."
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Robert, a 20-year-old from Cuba, has opened eyes with his blend of power and speed in his first big league camp. The White Sox signed him to a $26 million bonus last May.
"Obviously for us, a step back," White Sox manager Rick Renteria said. "We know it's not going to be an extended period of time. We didn't know anything during the game, but he came in the next day with some swelling and irritation. They looked at it and got it re-evaluated. We're looking at it as a little tiny setback, but he'll be back shortly."
Robert will be limited mostly to cardio activity before the cast is removed.
"Obviously, not an ideal situation," Hahn said. "But given that we expect him playing games in May is not too horrible. We didn't see a ton, but what we did see was very impressive, not just between the white lines during games, but the way he went about his business in drills, the way he fit in with his teammates in the clubhouse and his work ethic all fit in of a very professional approach.

"Given his tools and the work ethic, we continue to think of him extremely highly." Hahn said.
Robert is frustrated.
"It was a feet-first [slide]," Hahn said. "There was some traffic. It was just an unfortunate fluky thing."
Hahn said Robert would probably need two weeks in extended spring games before being assigned to an affiliate.

Robert said he was just getting into a rhythm with his confidence growing.
"Now this happened, and I feel bad," he said through an interpreter. "Because of the intensity of the game I didn't feel much pain. It wasn't until the next day, I was pretty sore."