The latest development had been known for at least the last several days. Sportsnet's Arash Madani was the first to report the order of the rotation early last week, and while the club initially declined to comment, Gibbons made it official following Sunday's 2-1 loss to the O's.
Estrada wasn't available to speak to the media following Sunday's late-afternoon announcement, but he is expected to hold an availability later this week. It's the first time in Estrada's career that he has been named a No. 1 starter, and it comes on the heels of a season in which he went 9-9 with a 3.