I would take a different approach here - what about dropping Aramis Ramirez in favor of Lieberthal.
You have Chipper on 3rd, so you should not need any other one here (besides in case of an injury, but we dont hope that would come into play) plus you have a VERY solid OF, so you dont need Chippers games there. And if you tell us, your league isnt that active, you still might find a very capable 3rd baseman on the wire, especially considering the depth at this position.
On the other hand, I know the Sandbox scoring system, and it really doesnt favor Becketts stats at least this season. For one reason, he will loose many points due to the Marlins bullpen (as Arlo said) - 10 points is a lot, on the other hand, I doubt we see Josh pitch a lot of complete games, as at least till now, they do not overwork his young arm, which too does cost some points in that scoring system.
But all in all I would not put him away, and send Ramirez to the wire. Getting Lieberthal (or maybe another catcher) is almost a must, as you can fill 2 Catcher slots, and you have to fill up that 162 games on that position!