Santiago agreed Wednesday with the Tigers on a minor-league contract that includes an invitation to major-league spring training.
Santiago allowed seven runs on nine hits and three walks while striking out eight over four innings in Tuesday's 11-0 loss to the Tigers. He did not factor in the decision.
Santiago will serve as the primary pitcher Tuesday against the Indians, James Fegan of The Athletic reports.
Santiago is slated to start Tuesday's game against the Indians.
Santiago has been confirmed as the White Sox's starter for Saturday's game against the Angels.
Santiago is tentatively scheduled to start Saturday, Doug Padilla of the Chicago Sun-Times reports.
Santiago (1-1) allowed five runs (four earned) on seven hits and two walks while striking out five across 4.2 innings to take the loss in the second game of a doubleheader Tuesday against the Tigers.
Santiago's contract was selected as expected ahead of his scheduled start in the nightcap of Tuesday's twinbill against the Tigers.
Santiago will be called up from Triple-A Charlotte to start the nightcap of Tuesday's doubleheader in Detroit, Daryl Van Schouwen of the Chicago Sun-Times reports.
Santiago allowed one run on three hits and one walk while striking out seven over five innings for Triple-A Charlotte on Tuesday.