Coach Mike Tomlin confirmed Dixon's role during his Monday press conference. Dixon ran the first-team offense in practice Monday.
Longtime Steelers backup Charlie Batch got reps with the second team. Batch and Dixon are the only healthy quarterbacks on Tomlin's roster while Ben Roethlisberger serves his four-game suspension for violating the NFL's personal conduct policy.
Byron Leftwich had been in line to start in Roethlisberger's absence, but he sprained his left MCL in the Steelers' final preseason game last Thursday. The Pittsburgh Post-Gazette reported that his knee was wrapped as he watched practice Monday.
The Associated Press contributed to this report.