Horton had a locker in the Citi Field visitors clubhouse but was considered a member of the taxi squad Friday.

Horton reached the majors thanks to a collaborative process that began during spring training in Arizona: "He's going to impact this team."

Cade Horton joins the Cubs' rotation with a high-octane fastball and dominant minor league numbers, but questions about his durability and pitch depth loom large ahead of his MLB debut.