Fantasy baseball players are a lot like stray cats. The more attached you get to them, the harder they are to get rid of.
And nothing attaches you to a third baseman (or a catcher or a shortstop or anyone on the Pirates) more than a seven-homer month. (Except, maybe an eight-homer one.)
Still, it's a sad fantasy reality that the best time to trade your best performers is exactly when they're performing their best. The cruel odds of baseball are that what goes up will surely come down (even if slightly). Just because someone is deemed a sell-high candidate, it doesn't mean he'll be a disappointment. It only means his value could be at an all-time high.
And just like a cat, it might sting to see him go. But think of how much better your place will smell in the long run.