Originally Posted by GIDP
Those guys sign as free agents though not exactly the same thing. I would guess if MLB allowed it to happen it would happen more often, and I cant think of a single time its happened.
Technically, GIDP is right. They wouldn't be able to make that kind of covenant. Here's why:
If you sign a Major League contract, you can sign for multiple years. You could stipulate such a covenant at the end of the Uniform Player Contract... however, since you're giving him a Major League Contract, this is a moot point.
When you don't sign a Major League contract, however, you're technically only signing a 1-year deal. You're signing a minor league contract that the club can renew from year to year. You can't really specify a covenant for a year that isn't covered by the contract itself.
So there are probably two things they could do: specify that he be added by a certain date this year (i.e. September 30), which would mean they have to release someone the last day of the regular season (ish), or they could simply make an oral promise to add him in November when the clubs submit their protection lists for next season.