Tomas was suffering from what manager Chip Hale said was altitude sickness, which was causing nausea and dehydration.
Danny Dorn got the start in right field in place of Tomas, batting sixth.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.