All that got them was another last-place finish.
So the 2013 World Series champions are rebuilding again, this time under new baseball boss Dave Dombrowski. But the ballclub has more reason to be optimistic at this point than it was last year.
''I'm proud of what we did here,'' interim manager Torey Lovullo, who guided the team to a 28-20 record after taking over when John Farrell was diagnosed with a treatable form of cancer, said after closing the season with a sweep by the Cleveland Indians.
''I couldn't be more thrilled with what they did to lead into 2016. With a couple of key additions I think we're going to be exactly where we want to be, and that's win a world championship.''
Here are some other things to look for as the Red Sox try to go from worst to first for the second time in four years:
KEY HITS: Jackie Bradley Jr. established himself as an outstanding defensive outfielder in two previous seasons. But in neither of those years did his batting average top .200.
Bradley finished with a .249 average this season - from Aug. 6 to Sept. 7, he batted .424 with seven homers and 32 RBIs. If he can hit the way he did this year, he will be hard to take out of the lineup.
Mookie Betts and Xander Bogaerts also showed they could be the core of a future contender. Eduardo Rodriguez was the most consistent starter on the staff. Henry Owens showed talent, if not consistency, in the rotation. At 35, Rich Hill only made four starts, but he struck out 10 batters in three of them and twice did not allow a run.
COSTLY ERRORS: The Red Sox locked up Sandoval and Ramirez, and now they could be eating those salaries to make room for a youth movement.
Ramirez finished the season on the disabled list, leaving him with a .249 average, 19 homers and 53 RBIs. Sandoval also ended the season injured, finishing up with a .245 batting average, 10 homers and 47 RBIs - all the worst in his career.
General manager Ben Cherington's other splurge was starter Rick Porcello, who was given a four-year, $82.5 million extension at the start of the season. He was much better in the second half (3.53 ERA) than the first (5.90), but still not the front-line starter his salary would indicate.
WINTER SHOPPING LIST: When Dombrowski was hired during a front-office shuffle that saw longtime team president Larry Lucchino move into semi-retirement, Cherington decided not to stick around. That leaves the former Tigers boss to clean up the mess.
Dombrowski's first job is to decide which of the young Red Sox he wants to keep, and which he can dangle as trade bait for the starting pitching the team lacked in 2015. If the team doesn't trade Ramirez, he could move to first base to clear the way for a young and exciting outfield of Betts, Bradley and Rusney Castillo.
COACHING QUESTIONS: Farrell announced on Aug. 14 that he had been diagnosed with lymphoma. Lovullo, his bench coach, took over and the team went 28-17 before a sweep in Cleveland to end the season cost the ballclub a chance to finish .500 and escape last place.
Dombrowski said the bulk of the coaching staff will be back, including Farrell if he's healthy. Lovullo agreed not to seek other managerial opportunities; what financial or career promises were made have not been disclosed. He could be ready to step in if Farrell's health - or the team's performance - doesn't improve.
AP Sports Writer Tom Withers in Cleveland contributed to this report.