As you know by now, Nico Hoerner suffered a hamstring injury in Tuesday’s game in Pittsburgh. Infielder Sergio Alcántara was pulled from Iowa’s game, apparently not for any injury reason, so he’s likely headed to Pittsburgh to replace Hoerner on the active roster. There is also this report, though:
Sergio Alcantara was removed from last night's game but I'm being told Rafael Ortega is actually the one being summoned by Chicago. Not sure if it's a taxi squad move or to fill the void for Nico Hoerner. But Ortega is now the guy.