In 2257, Haynes had been accepted into the Command Training Program aboard Discovery, along with Sylvia Tilly and Albert Kim, to prepare him for the command track. On stardate 1029.46, he completed a shipboard half marathon as part of the program in last place with a time of 9:16:22. He spoke briefly with Commander Saru on suggestions for improving.
He also participated in shadow exercises with the bridge officers, getting a chance to speak briefly with some of the bridge science officers including Linus before Ensign Tilly had an outburst and left the bridge. (DIS: "Point of Light")