Left wing Pascal Dupuis will miss at least a month with a sprained left knee sustained last Thursday. Right wing Mattias Weinhandl - felled by a concussion caused by a collision in Saturday's game - is also out. Foy, who played in 19 games with the Wild last season, and Smith were recalled from Houston of the AHL. Smith has been in 125 NHL games with Phoenix, Nashville and the New York Islanders.
Foy and Smith were tied for the Houston lead with four points each in five games.
The Wild (5-0), who begin a three-game road trip against Los Angeles on Wednesday night, are off to the best start in the franchise's six seasons.