I'm not impressed with the concept of using a career bench player, at age 33, as the outright starting outfielder. The Pirates, in my opinion, could come up with a better use for the playing time.
I liked the Diaz signing as a good complementary piece, but he is stretched too far as a starter. He could be a useful player, but the flaws here are apparent as well. He doesn't draw walks, has a below-average arm for right field, and, most of all, has trouble hitting right-handed pitching.
Over 849 career plate appearances against righties, Diaz has hit .269/.327/.382 for a .710 OPS and .312 wOBA. That's with a .336 BABIP that may or may not represent good luck. Given at least two-thirds of the majors' starting pitchers are right-handed, I don't see the production or upside.
Again, I don't get the concept here. If an everyday slot was needed to sign him, that would have been a dealbreaker for me. If that was the case, I would have stuck with Lastings Milledge on a one-year deal and found a platoon partner for him.
Nothing is definite, and Kovacevic may have misinterpreted the front office. Also, it's early and other moves could happen. Still, it's an interesting rumor. The Pirates are also reluctant to give up on Garrett Jones as an everyday player, suggesting that they aren't particularly interested in platooning him with Diaz, so it makes sense if this is true.
Diaz everyday would be preferable to Ryan Doumit in right field, at least.