Portland's All-Star third baseman has hit .375 with an OPS of .980 and 14 RBIs over his last 10 games, lifting his average to .304 with 16 homers, 25 doubles and 77 RBIs for the teams.
"I'm happy with it," said Middlebrooks, a fifth-round pick in 2007 out of Texarkana (Texas) High School. "But I'm not satisfied. I want to push through and finish strong."
Middlebrooks, who turns 23 next month, has played at one level each of his first four seasons in the Red Sox system. He hit .254 with Lowell of the New York-Penn League in 2008, then batted .265 with seven homers and 57 RBIs for Greenville in the South Atlantic League in 2009.
Last year he hit .276 with 12 homers and 70 RBIs in 435 at-bats with Salem in the Class A Advanced Carolina League. A football prospect in high school, Middlebrooks had the best arm at third base in the Carolina League last year, according to managers.
"I have no complaints. The guys in the front office, I trust their judgment," he said of not being promoted to Triple-A during the season.
Middlebrooks began the year by hitting .347 in April, and his only month below .300 came in May when he hit .237. He hit .371 in June and .302 in July as he continues to make solid progress.
"He's very professional," said Portland manager Kevin Boles. "He's very aggressive at the plate. He has a lot of offensive potential."
"He has produced -- no one can argue that," added Ben Crockett, Boston's assistant director of player development. "He uses the entire field."
The Sea Dogs are out of postseason contention, and the roster took a hit in late July when Chih-Hisen Chiang, Tim Federowicz and Stephen Fife were traded in a three-team swap with Mariners and Dodgers.
"It's bittersweet," Middlebrooks said. "At the same time, you are happy for them. They're three really good players and were three really good teammates."
Middlebrooks is ranked as the No. 4 prospect in the Boston system by MLB.com, and, at the rate he is going, could be in Fenway Park in the near future.
"I'm not going to get ahead of myself," Middlebrooks told The Portland Press Herald after picking up three hits Saturday against Erie. "One day at a time."
It was the third time in 10 games he collected three hits in a game.
The 6-foot-4 Middlebrooks has lost most of his Texas accent, he said, mainly since he is around players from all over the world. And he has enjoyed being part of Red Sox nation this summer in New England.
"It's awesome. We get huge crowds," he said.
Hello, Canada: Right-hander Henderson Alvarez was promoted from New Hampshire to make his Major League debut Wednesday for the Blue Jays in Toronto against Oakland. The 21-year-old went 5 2/3 innings but did not get the win in the Blue Jays' 8-4 victory. "It's exciting. You bring young, talented guys to this roster, regardless of position, but when you have the talent to go with youthfulness, yeah, it's exciting," Toronto manager John Farrell told The Standard. Alvarez began the year at Class A Advanced Dunedin in the Florida State League before heading to New Hampshire, where he was 8-4 with a 2.86 ERA.
Playoff push: The battle for postseason play is a capital idea in the Western Division. Bowie, just 10 miles east of Washington, D.C., is battling with Harrisburg and Richmond, which play in the capitals of Pennsylvania and Virginia, respectively. Harrisburg is one game ahead of Bowie and 3 1/2 ahead of Richmond. First-place New Hampshire is seven games ahead of Reading and Trenton in the Eastern Division.
Home, sweet home: Bowie outfielder L.J. Hoes has been on a tear for his local team, earning Orioles Player of the Month honors for July. Hoes grew up in Mitchellville, Md., less than 10 minutes from Prince George's Stadium. He is hitting .314 with six homers and 46 RBIs since his promotion from Class A Advanced Frederick.