The 23-year-old hit .625 (10-for-16) this week with three doubles, three homers, 10 RBIs and six runs scored in six games. He led the AL in batting average, slugging percentage (1.375), on-base percentage (.632) and total bases (22).
"It's an honor for sure -- I was just happy I could get some hits and help us win some games," Middlebrooks said. "I'm happy, I'm honored, it's awesome. But at the same time, it's one week, so hopefully I can keep it going."
With the trade of Kevin Youkilis to the White Sox, Middlebrooks figures to be slotted into the Red Sox's everyday lineup. But that won't change his approach or preparation before each game.
"Everything is going to be the same," Middlebrooks said. "I come here every day with the same intent to get better every day and help us win. I did the same things day in or day out if I was playing or not, so nothing really changes."
The Red Sox hope his production won't change either.
He singled, scored and notched an RBI double Tuesday, then hit a two-run homer in his only plate appearance Wednesday. On Thursday, the youngster hit another two-run shot to spark a three-run eighth inning in Boston's 6-5 comeback victory.
Middlebrooks was 3-for-4 in that game, Boston's fifth consecutive victory, including a pair of RBI singles.
On Saturday, the former fifth-round pick also went 3-for-4 with a single, double and home run while recording two RBIs for his fourth three-hit game of the year.
At that point, Middlebrooks had boosted his season average to .331 with nine homers and 33 RBIs, becoming just the fifth player since 1920 (when baseball began tracking RBIs as an official statistic) -- and the first since Albert Pujols in 2001 -- to reach those minimums in his first 40 career games.
"It's a nice honor, he had a great week," said Red Sox manager Bobby Valentine.
Middlebrooks leads all AL rookies in homers and RBIs, and is third in the league in hits, runs and doubles.
So was he surprised to win the award?
"I was. That wasn't even in the back of my mind, so that was pretty cool," he said.
Austin Laymance is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.