Lewis injured his surgically repaired shoulder when trying to tackle rookie wide receiver Brian Quick. The third-year safety fell to the turf before gingerly getting back up and leaving the game.
According to head coach Romeo Crennel, Lewis' injury isn't season-ending but it's unclear how long he'll be out, according to Arrowhead Pride.
"He injured the same shoulder he injured before," Crennel said. "It's a different injury. He doesn't have to have surgery or anything like that but he has to rest that shoulder and have him immobilized before we can start some movement exercises and see how quickly we can get him back."
Lewis has been a key piece to the Chiefs' defense, so losing him would be a significant blow. Newly acquired Abram Elam will step in and become the starter alongside Eric Berry in the meantime.
"I'm glad we got him, definitely," Crennel said, "because he's an experienced guy. He has a maturity level to him. I think he can handle the back end. He has shown us that he has been able to grasp the system and I think he'll do a good job in the back end for us."
Kansas City's next preseason game is a home date on Friday against the Seattle Seahawks.