BOSTON -- Tuesday marks an anniversary of sorts for Jackie Bradley Jr., though it's doubtful he will remember.

One year ago, the Boston Red Sox temporarily interrupted Bradley's banishment to Triple-A, recalling him before a game in Toronto. But Bradley's return to the big-league team lasted for only 12 days during which he got a total of 11 at-bats. On May 22, he was sent back to the minors, flip-flopped with fellow outfielder Rusney Castillo, who signed for $72.5 million late in the 2014 season in part because Bradley had failed as the everyday center fielder.

That all seems like such ancient history.

These days, Bradley is the hottest hitter on the American League's highest-scoring team, a status he punctuated Monday night at Fenway Park with three more hits -- including his first career grand slam -- and six RBIs in a 14-7 pummeling of the Oakland Athletics.

Jackie Bradley Jr. celebrates four of his six RBIs on Monday night following his sixth-inning grand slam. AP Photo/Charles Krupa

A sizzling Italian sausage on Yawkey Way has nothing on Bradley right now. To wit:

Bradley has a 15-game hitting streak, the longest active surge in the majors. He's 21-for-55 (.382) with four doubles, three triples, four home runs, 17 RBIs and a 1.215 OPS during that time.

At .903, Bradley has the 13th-best OPS in the American League, not terribly far from the likes of Mike Trout (.964), Eric Hosmer (.949) and reigning league MVP Josh Donaldson (.931).

Bradley has three homers in his past five games -- or as many as slugging teammate Hanley Ramirez has hit in 119 at-bats.

In the series-opener against the A's, Bradley put on a hitting clinic. In a six-run fourth inning against Oakland ace Sonny Gray, he tied the game with a two-run single to center field. In the fifth, he went the other way for a single to left field. And in the sixth, he pulled a two-strike curveball down the right-field line for his first grand slam since his days at the University of South Carolina.

"Jackie is in a good place," manager John Farrell said in what may qualify as the understatement of the season. "He's been more aggressive early in the count. It's paid dividends for him and us."

And to think, Bradley was all but an afterthought at this time last year.

Perhaps former general manager Ben Cherington deserves credit for not trading Bradley when he had an opportunity. Then again, Bradley's value wasn't particularly high after a 2014 season in which he batted .198 with a .531 OPS that ranked as the lowest by a player with at least 400 plate appearances since Los Angeles Dodgers shortstop Alfredo Griffin (.512) in 1990.

At this rate, though, opposing GMs must be kicking themselves for not being more aggressive with offers for Bradley. Or maybe Detroit Tigers GM Al Avila will just kick his predecessor, Red Sox president of baseball operations Dave Dombrowski, who expressed interest in Bradley before trading for Anthony Gose in November 2014.

"It was pretty obvious that we were scouting [the Red Sox] pretty heavily and on them pretty good," Sox first-base coach Ruben Amaro Jr., the Philadelphia Phillies general manager from 2009-15, said recently. "We knew that Jackie Bradley was a very, very good defender. I'm not sure we knew he was THAT good."

Notice Amaro didn't say anything about Bradley's hitting. Until last August, there wasn't much to say.

But shortly after being called up again from Triple-A, Bradley went on an 83-at-bat tear in which he batted .446 with 24 extra-base hits and an otherworldly 1.441 OPS. It was enough to convince Dombrowski, hired by Red Sox principal owner John Henry midway through Bradley's surge, that Bradley merited another chance to be the everyday center fielder.

While others players, including Castillo in left field, had to fight for their jobs in spring training, Bradley was largely unchallenged. And as Castillo began the season on the bench and ultimately wound up back in Triple-A, the Red Sox stuck with Bradley despite a slow start at the plate.

This latest hot streak is reminiscent of last year's, not only for its sheer volume of hits but also the all-field approach and the confidence with which Bradley is stepping to the plate.

"I never lost confidence. Never," Bradley said. "I wouldn't know how tough it would be to regain. I think it's just a sign that I'm kind of taking what's given to me. If they pitch away, I just want to be able to square it up. I'm not thinking about going the other way. I'm just thinking about putting the fat part of the bat on the ball and wherever it goes, it goes."

Bradley is hitting the ball harder than just about any of his teammates, save perhaps for ageless slugger David Ortiz, and his emergence as one of the best center fielders in the game is a sight to behold, especially considering where he was a year ago.