Two Billings Mustangs promoted to Dayton

Derrik Lutz was promoted to Dayton earlier this week and it just slipped my mind to talk about it. He actually pitched yesterday for the Dragons.
2nd round pick Sean Watson was also promoted to Dayton. He is with the team, but a roster move has not been made yet.
Does this mean he will take the rotation spot of Zach Ward and Ward gets promoted? Or will Watson come out of the bullpen as a long guy every 5 days?