Mesoraco needs to play. He's not like Ramon Hernandez, who needs to rest. You stunt his development as a receiver and as a hitter if he's sitting half the time. As Brutus notes, you're burning a year of service time while you do that. He'd be better off in AAA.Why wouldn't Hanigan and Mesoraco be a full time platoon? At least for a year? Who does it hurt? Hanigan gets rest, like he did in 2010, while Mesoraco gets his feet wet. Not only that, they would both likely be good seventh place hitters, Hanigan showing on-base skills and Mesoraco power.
Between them (again, if Mesoraco continues to hit as he did in 2010), you could see a line of 280/350/450 next season.
That sounds like a great platoon to me.
No team platoons its high ceiling prospects all year long.