The newest member of the Red Sox is Conor Jackson, who was acquired in the middle of the night for Triple-A reliever Jason Rice. Jackson is expected to be used as a utility player (at least in theory -- his defense leaves plenty to be desired), a job that was hard to envision for him just a few years ago. That's because, at one point -- well before he was a part-timer for Oakland -- Conor Jackson was one of the better prospects in the game.
Jackson was the 19th pick overall in the 2003 amateur entry draft. The 21-year-old right-hander hit .319/.410/.533 in his first 300 plate appearances of pro ball that same year, and followed that up with a strong 2004 showing in which he hit .324/.406/.512 between High-A Lancaster and Double-A El Paso.
Lancaster is an insane park for right-handed hitters, so it's hard to put too much stock into his .345/.438/.562 line from that season. His time with El Paso was good (.301/.367/.456) but not great, but the Diamondbacks popped him into Triple-A for 2005 anyway. Baseball America rated Jackson the #40 prospect in the game heading into 2005, and he made good on that by hitting .354/.457/.553. Of course, Tucson, as a team in the PCL, is also hard to put too much stock into. Jackson's line is good, there's no doubt about that, but the average hitter in the PCL that year had a line of .278/.350/.442, so Jackson's line wasn't as impressive as it looked at first glance.
Baseball America rated Jackson the #17 prospect in all of baseball heading into 2006, just in time for him to put the minor behind him and stick in the majors. Jackson would hit .292/.371/.451 over the course of his three full seasons in Arizona, three above-average but not exactly great campaigns (his wRC+ for those three seasons: 105, 110, 114). As his minor league numbers made him look like a total monster, he was considered something of a disappointment.
This is right about where he should have been expected to perform, though. The reason Jackson pushed his slugging over the .500 mark on most occasions in the minors was due to his batting average, which, at its lowest, was .301 in his stint with El Paso. He usually hovered around the .200 Isolated Power mark, a fact that would be more impressive if not for where he did it -- seeing him turn into a high-average, high-on base percentage hitter with 15 homer power was only surprising if you let Lancaster and the PCL do your thinking for you.
The real problems started during 2009, when Jackson contracted Coccidioidomycosis, or Valley Fever, in May. He lost 35 pounds during the illness, and spent the rest of the season recovering and then playing in High-A.
He has not been the same since, as he's hit .244/.323/.336 with the Diamondbacks and Athletics over his last 609 plate appearances, including a .252/.348/.352 showing against left-handers. This former top prospect and above-average hitter was just dealt for a minor league pitcher Boston likely moved because they weren't planning to protect him on the 40-man roster this winter, and it's possible he's there to soak up September at-bats with the rest of the 40-man call-ups, not even as a real possibility for the playoff roster.
Jackson's stock has fallen a long way since he was drafted, but with Kevin Youkilis on the DL and Adrian Gonzalez lacking a real backup at first, he may just fit into Boston's current needs, even if he isn't part of their long-term plan for 2011. At the price, it's hard to ask for more, but it does serve to remind us all of just what could have been with the former Arizona prospect.