I confessed in a lengthy pre-season missive that I’ve owned Justin Upton in my primary keeper league for a long time, so it’s not easy for me to untangle years of pent-up frustration/hope/rage from analysis on this particular player. But I find him interesting beyond my vested interest, as he’s teased dynasty leaguers so uniquely and unmercifully with his immense raw talent year after year. And with each failure to ultimately live up to that promise he’s retained – and still does retain – the trump card of still, somehow, being a player only just now entering his physical prime. We’re heading towards 150 plate appearances into the 2014 season now, when several important statistical measures have begun to stabilize. So how’s Upton the Younger doing, and what should you do about him in dynasty leagues?

Last season Upton went on a well-publicized world destroying mission in April, posting a .298/.402/.734 line with 12 homers, 19 RBI, and three steals. The effort was good for a 208 wRC+, and positioned him as the most valuable player in fantasy baseball for the month. Well, here we are this year, and he more or less did it again. His .326/.400/.641 triple slash encorewas good for a 189 wRC+, to go with seven homers, 13 RBI, and a pair of stolen bases. You probably didn’t hear nearly as much about his start this year if you don’t own him, in part because Upton spent nigh on the entire year after April last season tormenting his fantasy owners with an even-more-painful-than-it-sounds .256/.335/.409 line with 15 homers, 51 RBI, and 5 steals over his next 531 plate appearances. The hot start buoyed him to the 24^th ranking among outfielders per ESPN’s Player Rater, but given how hot that start was you can see just how ridiculously unimpressive the next five months were.

So now that we’re here again, what do we do? Well, there are warning signs flashing all over the place right now, even moreso than last year. Upton’s 2013 April happened despite a moderately worrisome 30:16 strikeout-to-walk ratio. The whiff rate worked out to a fairly ugly 26.8% number, though it improved marginally to a shade under 25% as the season progressed. This season? Hoo boy. Upton put up his strong first month despite a strikeout rate that leapt up to 31.4%, and after a cool streak to start May that number now sits at a positively Mark Reynoldsian 34.1%. His .303 average is propped up by a .415 BABIP that is not remotely supported by a middle-of-the-pack line drive rate and top-20 flyball rate.

But perhaps the most notable takeaway from the early season data returns is that he’s seeing a notable and significant jump in the number of fastballs coming his way, and that appears to be a clear product of leaguewide scouting reports. Despite exhibiting a strong batting eye and lying off a solid rate of fastballs out of the zone, his 34% whiff rate on in-zone fastballs is classified appropriately by Brooks Baseball as a “disastrously high likelihood to swing and miss.” Sure enough, the change in attack has resulted in a leap in Upton’s swing rate (+5%) and a pretty terrifying corresponding movement of his SwStr% from a career rate under 12% all the way up to 15%.

Oh, and his HR/FB rate is currently sitting at almost double his career rate as well.

Add it all up, and that’s an ugly dossier of negative indicators for performance going forward – one that does not at all suggest that Upton’s strong surface start is evidence that he’s finally turned the corner as he enters his physical prime. Nigh on every indicator of successful hitting has not only failed to improve over the past couple seasons, but is instead regressing at a fairly rapid pace right now. By the numbers dynasty owners should be looking to peddle Upton’s topline April success as evidence of an ascent into his prime and try to cash in while the name recognition and early numbers are enough to fetch an elite or near-elite return.