He doesn't lose a year, he gets a full season if he comes in first of second regardless of when he comes up (i.e. if the Sox hold him down until June, but he balls out he still earns a full year of service time). Since he wasn't on the roster early enough, the Sox are not eligible for the pick for Roman only Kristian. 🫣
I was ineloquently trying to say that holding him down now doesn't necessarily get you the 7 years that a lot of people are saying it does. The Sox lose that 7th year of control if he comes in 1st or 2nd.