KFFL.com's Fantasy Baseball Diamond Market gives you candid reviews and ratings of fantasy baseball players making MLB news in your rotisserie or head-to-head baseball leagues. Are they trade bait or worth your FAAB dollars in your fantasy baseball games?

Wilin Rosario, C, Colorado Rockies

The power was the reason you took a chance on Rosario. But on the heels of a solo job Tuesday and a torrid 13-game stretch (23-for-52, four home runs, 11 RBIs), his 27 taters in 369 at-bats this year have surpassed expectations for single-year owners.

Colorado is still waiting for the leather to catch up to the 23-year-old's bat work, though, just like fantasy owners were prepared to wait for his contact skills to catch up to his thump. He's hitting .276 so far, which is backed up by a normal .294 in-play clip, which has some credence because he has a 47.5 grounder percentage.

Of course, you'd be more complacent if he could improve on his woeful contact rate (72.2 percent), high empty-hack percentage (13.8) and low walk frequency (5.6). Those marks say the BA won't hit those heights next year without some drastic changes to his approach.

Maybe the alluring .313 opposite-field batting average says he can keep it up, but you might have to pay a top-10 mixed league price next year to find out, and he has too many pitfalls in his game to be worth that in BA formats. If you can get him as a No. 2 backstop, that's a sweet profit opportunity considering his home environment. It'll be harder to sneak him past your opponents, though, thanks to his scorching end to 2012.