On Opening Day, absolutely. Winder, Sands, Henriquez, Megill, Moran, even Alcala if he looks off. Some pitcher will be on the injured list within 2 weeks and someone else can come up. It's impossible to keep 13 pitchers healthy at the same time.
Just look at last April:
Before the season started - Cody Stashak injured, Jharel Cotton added.
4/12 - Alcala to the injured list, Dereck Rodriguez added to the roster
4/17 - Sonny Gray to the injured list
4/20 - Jhon Romero injured
4/30 - Bailey Ober injured
5/6 - Dylan Bundy injured
5/10 - Chris Paddack injured
5/11 - Danny Coulombe injured
5/21 - Winder injured
5/22 - Stashak injured
5/25 - Joe Ryan injured
5/28 - Coulombe injured
That's just April and May and they used the injured list for pitchers 11 times.
Let's avoid using quad-A players like Cotton, Coulombe, Minaya, Rodriguez and Smeltzer or bringing up rookies too soon like they did last year with Sands, Moran and Cano.