Robinson posted Wednesday on his personal Twitter account that he underwent Tommy John surgery earlier in the week.
Robinson, whom the Cubs selected in the ninth round of the 2016 first-year player draft, posted a 4.76 ERA and 1.46 WHIP in five starts for Triple-A Iowa before being placed on the 7-day injured list April 28. The circumstances surrounding Robinson's absence for the past month weren't known, but the right-hander has now provided some clarity on the matter. Given the timing of his surgery, Robinson will miss the remainder of the 2019 season and most -- if not all -- of the 2020 campaign.