Will Middlebrooks was a very successful high school player in Texarkana, Texas, a prospect as both a hitter and pitcher. He was considered a first-round talent by many experts for the 2007 draft, but a strong commitment to Texas A&M scared teams off. The Red Sox picked him in the fifth round and convinced him to enter pro ball with a robust $925,000 bonus.
His development was slow at first: he hit just .254/.298/.368 in 59 games for Lowell in the New York-Penn League in 2008, lacking home run power and struggling with the strike zone. He improved somewhat in 2009, hitting .265/.349/.404 in 103 games for Low-A Greenville in the Sally League, but still struck out 123 times in just 374 at-bats. He showed more power in 2010, hitting .276/.331/.439 with 12 homers for Salem in the Carolina League, but his strikeouts remained excessive.
2011 was different: his bat exploded for Double-A Portland, with a .302/.345/.520 mark and 18 homers in 96 games. He still had some issues with the strike zone, especially after he was promoted to Triple-A Pawtucket, where he hit .161/.200/.268 with 18 strikeouts in 56 at-bats. Still, the progress was obvious, and he was particularly impressive on defense.
Middlebrooks is off to an excellent start in his second Pawtucket trial, hitting .333/.380/.677 with nine homers already in just 24 games. He's reduced his strikeouts this year, whiffing 18 times while drawing seven walks in 93 at-bats. The sample is small, but this is the lowest strikeout rate of his career and, not coincidentally, the strongest production.
A 6-4, 225 pound right-handed hitter, the 23-year-old has made steady improvements refining his swing and tapping into his natural strength, showing power to all fields. The strike zone was little more than a vague suggestion early in his career, but he's gradually boosted his ability to control it. It is still a weakness at times, but not a crippling one. He's a very good defender at third base with above-average range, a strong arm, and reasonable reliability. Although his actual running speed is below average (his only weak tool), he's stolen 35 bases in 44 career attempts. He might pick up a few steals here and there early in his career if pitchers ignore him.
The pre-season plan was for Middlebrooks to spend the year in Triple-A and push Youkilis in 2013, but the veteran's injury and Middlebrooks' hot start moved up the timetable. Contact is still an issue for the rookie and, with just 40 games of Triple-A under his belt, I suspect he'll be quite streaky at first. Nevertheless, he's come a long way over the last three years, and should be starting regularly this time next year.