Dioner Navarro is probably the most hated Rays regular of the year thus far. Not that people literally hate him, but relative to all other players, Navarro's jerseys aren't flying off the hangers for wearing. Let's talk about his offensive struggles thus far.
O-Swing%: 26.1% (Career: 22%, 2008: 23.2%)
Swing%: 46% (Career: 45.2%, 2008: 45.4%)
Z-Contact%: 87.5% (Career: 92.4%, 2008: 94.4%)
Contact%: 80.2% (Career: 85.6%, 2008: 88.9%)
Zone%: 49.1% (Career: 52.3%, 2008: 52.3%)
Basically, Navarro is seeing far less strikes than usual, and for whatever reason, he's swinging out of zone. Why? Well, I don't really know. Perhaps Navarro is paranoid about the strike zone expanding without his knowledge, or he's just pressing. This wouldn't be much of a concern if his contact on pitches in zone weren't down to a career low 80%. That implies that Navarro is either having issues with his recognition, vision, bat control, or bat speed. None of those things deteriorating are particularly good.
Obviously there's still a ton of season to play, but these things usually stabilize quickly unless there's something else going on. Look at B.J. Upton's contact rate, it's obvious his bat is still in spring training mode, and he's making far less contact than usual because of it.
If it is a recognition thing, maybe the sudden change in attack against Navarro is to blame. More fastballs and curveballs, less change-ups and sliders so far. As Navarro sees less of A.J. Burnett and Josh Beckett, those ratios should move a bit.
Navarro's line drive rate is way down and his BABIP is only .233 (career: .290). It doesn't help matters that he's refusing to walk while striking out more. Don't dump Navarro out in the bath water quite yet, but do recognize there's a flaw in his offensive profile right now, and it's costing him.