Well, right now he's in the rotation even if Suarez is ready go on Day 3.
I think that while it's true you can never have enough pitching, you also don't need quite as much from your 4-5-6-7 pitchers as you think you do. Walker way outperformed (even if he was also overpaid) as a 4. And while Falter was obviously not good enough to stick as a 5 he was still a bit of an outlier in that they lost so many of his starts. Of course the team wasn't scoring runs in the first two months either.
I'm sure they'll bring some AAAA arms and potential swingmen in on minor league deals. The only real question is whether to sign a Strahm type or a shorter-burst late-inning type as the big bullpen signing.
But it's also very early! A trade still very possible though I bet it's for an OF rather than either kind of pitcher. Trade deadline or Abel to complete that puzzle in August, if they don't get Yamamoto.