The Giants appear to have a plethora of backup catchers in the organization and Andrew Susac seems like the "catcher most likely to move Buster Posey to 1B", so Monell simply gets crowded out. Pegeuro may develop into a useful backup OF with some speed, but again he simply gets lost in a mix of guys who seem just good enough to impress for a week or so, but not long-term.
from MLB Daily Dish:
Giants considering futures of Johnny Monell, Francisco Peguero - MLB Daily Dish:
To make room for newly-added pitchers Erik Cordier and Jose De Paula, the San Francisco Giants designated catcher Johnny Monell and outfielder Francisco Peguero for assignment. The team has ten days to either trade, waive or release the two players, and sources have indicated that each should find a new home soon.
'via Blog this'
In the upcoming Rule 5 Draft, the Giants are protecting their favorites and leaving the rest to dangle. I can't see them losing a bat, although maybe somebody takes a flyer on a Jarrett Parker. Maybe a pitcher who needs a change of scenery will get plucked from the organization, but the Giants seem to have arms a plenty, especially at the A level.
from Baseball America:
San Francisco Giants (37)Likely Protections: OF Gary Brown.
Possible Protections: 3B Adam Duvall.
Brown has been a little disappointing as he has reached higher levels, but speed and defense make players like him attractive, especially when you consider that he’d be playing for the major league minimum salary while providing 80-grade speed. Duvall isn’t great at third base, but he has legitimate power potential and he draws a few walks.