How bad and for how long would the young players have to play before being sent to the minors?

The Royals project to start the year with five position players who have less than a full year of major league service time -- Eric Hosmer, Johnny Giavotella, Mike Moustakas, Lorenzo Cain, and Sal Perez -- plus a 25-year-old shortstop, Alcides Escobar, who has yet to establish his bat in the majors. Setting aside the issue of how well you think they will perform (which has been addressed repeatedly this offseason and certainly will be addressed several more times before Opening Day), how bad and for how long do you think these six players would have to perform before the Royals would bench them or send them back to the minors?

The answer should be different for each player. For example, Escobar has the most major league experience, plays a difficult defensive position very well, and does not really have a viable replacement on the roster (with viable for purposes of shortstop meaning not Yuniesky Betancourt). Given that this is the team that let Tony Pena Jr. start for almost two years, Escobar probably has a longer leash. Giavotella, on the other hand, probably has a shorter leash due to his less experience, his major league performance last year, and the presence of a (semi-) viable replacement in Betancourt.

So given all potential factors (and saving any discussion for how well you think they will actually perform), what would it take for the Royals to bench or send down Hosmer, Giavotella, Moustakas, Cain, Perez, or Escobar this year?