Gray has only thrown 3 1/3 innings since Sept. 28, so he’s scheduled to throw a simulated game Thursday at Minute Maid Park.
The Yankees made the announcements Thursday afternoon, less than 24 hours after they knocked off the Cleveland Indians in the decisive Game 5 of the AL Division Series.
Tanaka pitched Game 3 of that series, striking out seven, walking one and allowing three hits in a 1-0 victory in New York.
Tanaka will oppose Astros left-hander Dallas Keuchel in the series opener. The two also met in the 2015 AL wild-card game, with Keuchel and the Astros winning 3-0.
Justin Verlander will take the mound for the Astros in Game 2.