While the Red Sox are in last place in the American League East, their top prospect is on fire in Triple-A Pawtucket.

Third baseman Will Middlebrooks homered for the fourth straight game today, taking Durham (Rays) lefthander Alex Torres deep over the right-field fence for his seventh home run in 16 games. The 23-year-old righthanded hitter is now batting .379/.406/.742 through 69 plate appearance with more extra-base hits (10) than strikeouts (nine) and is tied for second in the minors in home runs.

While Middlebrooks will probably never draw a lot of walks, he's made tremendous improvement in his hitting approach since signing with the Red Sox in 2007. He spent the first year of his career struggling in short-season Lowell in 2008, when he couldn't get his OBP above .300 and had a hard time tapping into his plus raw power early in his career in the lower minors.

The breakout year came last year, when Middlebrooks hit 23 home runs and a cumulative .302/.345/.520, with most of his damage coming at Double-A Portland before a late promotion to Triple-A. Middlebrooks has plus power to the middle of the field and showed last year that he could routinely drive the ball out of the park to the opposite field. Now he's starting to show he can turn on the ball and hit balls out to any part of the park in games; two of his home runs have gone to left field, one to left-center, two to center field, one to right-center and today's flew over the wall in right field. Scouts have said he's showing that he can turn on good fastballs inside and go the other way when he's pitched on the outer half.

With Kevin Youkilis off to a sluggish start in Boston, is it time to bring Middlebrooks up? That's probably premature. Yes, Youkilis is 33, and while his offensive production dipped last year, he still showed he could get on base at a high clip with solid-average power and has been a 4-6 win player each of the last four years. Middlebrooks is off to a terrific start and plays excellent defense, but he has just 32 games of Triple-A experience, about half of which didn't go so well when he got there last year. At some point this year, Middlebrooks may force the issue. For now he's probably staying put in Pawtucket, but he's not far away.

Update (6:01 p.m. ET): According to several Red Sox reporters, Youkilis just left today's game with a bruised left quad. Obviously his health and availability will have a significant impact on Middlebrooks' timetable, so it's possible his ETA to Boston just got expedited.