Lopez was placed on the minor-league disabled list with a broken left thumb, Jeff Sanders of The San Diego Union-Tribune reports.
Lopez began the season as the youngest player in the Midwest League and has a .224/.280/.358 slash line with 80 strikeouts in 246 at-bats for Low-A Fort Wayne. It remains unclear how long the 18-year-old will be on the disabled list or whether he requires surgery, but the TinCaps should be without the young shortstop for the foreseeable future.