After months of buildup, today is the day when MLB's trade deadline will finally come and go. And the trades have already begun.

From D-backs pitchers to a whole lot of Orioles, here are the players you should watch as the 6 p.m. ET deadline nears -- and their best fits.

Plenty of teams have reason to act — though the Padres, Mets and Yankees should be particularly motivated to get some deals done.