NATIONAL HARBOR, Md. -- After dealing away their top two relievers at the non-waiver Trade Deadline, the Brewers flipped another late-inning arm for multiple players on Tuesday, sending Tyler Thornburg to the Red Sox for infielder Travis Shaw, two prospects and a player to be named later or cash.
Shaw, 26, gives the Brewers a left-handed-hitting third baseman and allows Major League stolen-base leader Jonathan Villar to shift to a better fit at second. Just as critical to the deal are the two prospects coming to Milwaukee; Mauricio Dubon, a 22-year-old shortstop who joined MLBPipeline.com's list of top Brewers prospects at No. 9, and 21-year-old right-hander Josh Pennington, who ranked No. 22 in Boston's midseason Top 30 prospects list but fell just outside of Milwaukee's Top 30. The Brewers and Red Sox have six months to agree on whether the final piece will be cash or an additional prospect.
"There is clearly a lot of interest in relievers, in general, in baseball right now," said Brewers general manager David Stearns. "It was no surprise that given the way Thorny finished the season, he was going to be one of the most sought-after relievers."
A former top Brewers prospect who pitched in every imaginable role before finding a niche in the late innings, Thornburg was arbitration-eligible for the first time after finishing the season as the Brewers' closer in the wake of Aug. 1 trades that sent Jeremy Jeffress to the Rangers and Will Smith to the Giants. He made a career-high 67 appearances with a career-best 2.15 ERA, with a 34.2 percent strikeout rate that ranked 12th among pitchers who logged at least 50 innings.
Boosting his value to the Red Sox, Thornburg is under club control for three more seasons.
"I'm fairly surprised, not going to lie," Thornburg said. "But I'm definitely excited for the opportunity. I'm going to miss Milwaukee like crazy, but I'm excited to be playing for the Red Sox now."
With Thornburg gone, the Brewers' internal candidates to close games include 25-year-old Corey Knebel and 26-year-old Jacob Barnes, though manager Craig Counsell dislikes labels and would be likely to use different pitchers for save situations early in the season. Stearns and the Brewers have also been in contact with representatives for free-agent relievers.
Shaw has logged 778 plate appearances in the Major Leagues over the past two seasons, the majority of them in 2016, when he slashed .242/.306/.421 with 34 doubles, two triples and 16 home runs in 145 games for the Red Sox. He made 99 starts at third base and 28 starts at first.
"It will be different," Shaw said of the move from World Series-or-bust Boston to the rebuilding Brewers. "Baseball is a weird sport; teams can come out of nowhere and the rebuild process can happen quicker than most people think.
" … I'm looking forward to this new start in Milwaukee."
It's been real Boston ������excited for the opportunity ahead of me in Milwaukee! Looking forward to this next chapter in my career! #Brewers
Dubon, born in Honduras, joins a Brewers system that already has three players who began as shortstops among its Top 30 prospects, plus Villar and Orlando Arcia in the Major Leagues. Dubon made it to Double-A in 2016 before his 22nd birthday and hit .339/.371/.538 with 32 extra-base hits in 62 games.
Stearns didn't rule out Dubon beginning next season as a 22-year-old at Triple-A.
"We think he is a viable Major League shortstop in the future," Stearns said. "We also think he has the versatility to move off of that position if that is the best path for him as a Brewer. He could probably [play] everywhere on the diamond. He is a very athletic, baseball-savvy kid."
Pennington underwent Tommy John surgery as an amateur and fell to the Red Sox in the 29th round of the 2014 Draft. He has made only 20 professional appearances over two seasons, going 5-3 with a 2.86 ERA in 13 starts at Class A Short-Season Lowell in 2016. His 94-98 mph fastball was rated one of the best in Boston's system.
"He pitched healthy all of last year," Stearns said. "We are excited to bring that kind of high-upside arm into the system."
Thornburg, meanwhile, took his arm to the Red Sox, who made an even bigger splash four hours later by trading for White Sox ace Chris Sale.
"It's pretty much a whirlwind right now as far as catching up on calls and texts and everything like that," Thornburg said. "Hopefully in the next couple of days, I'll start getting extremely excited about the opportunity of winning a World Series."
Fantasy spin | Fred Zinkie (@FredZinkieMLB)
After posting a 2.15 ERA with a 0.94 WHIP and a 12.1 K/9 rate last season, Thornburg instantly becomes one of the premier non-closers in the Junior Circuit. Setting up for Craig Kimbrel, the right-hander should produce the necessary stats to be a lineup fixture in AL-only formats. Back in Milwaukee, either Knebel (4.68 ERA, 1.47 WHIP in '16) or Carlos Torres (2.73 ERA, 1.15 WHIP in '16) could emerge as the ninth-inning man.
As the newest member of the Brewers, Shaw walks into an uncertain role. The 26-year-old could help deep-mixed-league teams as Milwaukee's third baseman against right-handers (.762 OPS vs. RHP in '16) if the club moves versatile spark plug Villar to a different position -- such as second base. Meanwhile, veteran Pablo Sandoval and utility man Brock Holt should compete for the Red Sox's hot-corner job during Spring Training.
Adam McCalvy has covered the Brewers for MLB.com since 2001. Follow him on Twitter @AdamMcCalvy, like him on Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.