Ever since Ian Desmond first came up last fall and proved that his bat will play, Jim Riggleman has been wanting to turn him into a super-sub utilityman.
It's somewhat understandable, if you're only thinking about how to win the next game, and you believe in Cristian Guzman and Adam Kennedy (nevermind what it says about you if you believe in Cristian Guzman and Adam Kennedy). All managers, at least those in the NL, like to have a guy they can shuffle around all over, and Riggleman is correct that Desmond has the arm and athleticism to perform adequately at every position on the diamond, except presumably pitcher and catcher (though really who knows?).
Last fall, Rizzo ok-ed Riggleman's line-up noodling, even specifically signing off on the spur-of-the-moment decision to start Desmond in right field.
But this spring it appears that Rizzo has done the right thing and laid down the law: Desmond is a shortstop, he needs to focus on being a shortstop, and whether he's in DC or Syracuse, he needs to play every day.
From a development perspective, it's clearly the right decision. You don't get better sitting and watching, and it's harder to master a new level when you're also learning a bunch of new positions.
Now, if the Nationals were contending, and Desmond could help them win another game or two as the first guy off the bench, then I'd be all for using him that way. But they're not, so the priority should go on doing everything possible to set the kid up for success long-term.
Good for Mike that he's setting the right priorities and isn't afraid to make a clear and decisive call down the chain of command.