Smith will start Thursday's game against the Pirates, James Fegan of the Chicago Sun-Times reports.
All 10 of Smith's major-league appearances have come out of the bullpen, during which the 23-year-old lefty has allowed just one earned run in 16 innings while striking out 23 batters. His strong performance will now buy him the chance to make his first career start in the big leagues, though he may not work deep into Thursday's contest after throwing fewer than 40 pitches in each of his last three outings.