Xander Bogaerts was a bust.

The Aruban infielder, signed by the Red Sox as a 16-year-old in 2009, arrived in the big leagues briefly in 2013, moved into a full-time position in 2014 … and by the end of his rookie season had impatient Boston fans ready to discard him and move on. He flailed at pitches out of the strike zone, couldn’t get on base enough (a .297 on-base percentage) to use his speed, and had problems throwing the ball to first base.

Jackie Bradley’s rookie season was a .198 disaster, with 121 strikeouts. Two months after Mookie Betts’ debut, he was batting .228 and hearing that he was “just another Bradley.”

No, building with prospects isn’t easy.

“This is such a different environment up here, it’s just not easy for a young player to step right in. But it’s so results-oriented, that’s what we expect them to do,” Red Sox manager John Farrell said last weekend during Boston’s annual visit to Target Field. “As a manager, you have to understand that the talent you see … will eventually play out on the field. It’s there, but you have to be patient.”

It’s paying off just the way the Red Sox imagined. Bradley owns the longest hitting streak in baseball this season, a 29-gamer. He’s in the top 10 in slugging in the AL and is hitting .304. Betts, only 23, leads the league with 60 runs scored, has 14 home runs from the leadoff spot and is 11-for-11 in stealing bases.

And Bogaerts? Just ask the Twins. “He’s kind of doing it all for them,” manager Paul Molitor said after Bogaerts went 10-for-15 in three games at Target Field, drove in eight runs, smashed a pair of home runs, made a diving stop on defense and victimized the Twins with a clever, heady baserunning play.

Bogaerts, still only 23, is a legitimate MVP candidate at this point, leading the AL with 97 hits and a .352 average. “It’s not a surprise. I once saw him hit the ball completely over the batter’s eye in Akron,” said Twins reliever Ryan Pressly, who was teammates with Bogaerts and Bradley in the Red Sox farm system. “He was really raw, but you could tell he had the talent to be really good.”

The Red Sox trusted that, and it’s produced one of the great offenses in recent history. Boston is on pace to score 938 runs this season. Only the 2007 Yankees have surpassed that total in the past decade, and no team has reached 900 runs since 2009.

Veterans Dustin Pedroia and especially David Ortiz — enjoying one of the five greatest seasons in history by a player past his 40th birthday — are powering this juggernaut, too, but it’s the young players who particularly excite the Red Sox.

“When you have young guys hitting the way everybody is hitting out here, the whole focus is not on me,” Ortiz said. “The pitcher’s got to focus on seven guys, so I really appreciate the rest of the guys doing really well.”

And there are more to come. Blake Swihart is hurt, but he projects as a potential left fielder, eventually. Travis Shaw shows signs of flourishing at third base, and Christian Vazquez might someday be a premier catcher, though he is enduring the sort of break-in season that Bog­aerts went through.

“It takes time, and that’s not always easy in this business,” Farrell said. He was speaking of his own team, but acknowledged the Twins are going through their own painful maturation process, one that’s resulted in a shockingly ugly 2016.

The Red Sox manager preferred not to analyze the Twins’ difficulties, but did allow that, “we know they’ve got a lot of talent coming up. We saw it in spring training.”

In Boston, they’re seeing their own young talent flourish during the regular season, too.