Richards will be the bulk reliever in Sunday's game against the Tigers, Juan Toribio of MLB.com reports.
He is with the big-league club Saturday but won't be activated until Sunday. Richards has given up one run while striking out eight over 5.1 innings in three appearances at Triple-A. He has not gone more than 2.1 innings in that span, however, so even if the primary pitcher goes one inning, Richards is not a lock to go deep enough to qualify for the win.