I think that Robles starts the season in DC, but if Rizzo decided to try to wait until 6/4 he could always reverse that and bring up Robles at any time.
In that case who would be the 4th OF? Stevenson? I agree that Robles is likely to be our starting CF with Taylor on the bench. We do probably need to think about adding another veteran OF at some point for the inevitable Eaton DL stint.