Gomes, 28, was hitting .165 with eight home runs and 32 RBIs when he stumbled running over first base Sunday and suffered a separated shoulder.
That left the starting catcher's job for the next couple of months in the hands of Roberto Perez, who has just 339 at-bats over three seasons.
Brantley had an MRI on Wednesday after developing soreness in his surgically repaired right shoulder while on a rehab assignment with Class AA Akron. He is scheduled for more tests Thursday and the Indians don't expect an update until Friday at the earliest.
Brantley has played in just 11 games this season.
Lucroy went into Wednesday with a .305 average, 12 home runs and 45 RBIs for Milwaukee.