The good vibes that swept through Red Sox spring training camp, and across Red Sox Nation fandom last week with the blockbuster free agent signing of longtime Houston Astros third baseman Alex Bregman, suddenly took on a sour taste Monday.

Rafael Devers, the Red Sox’s incumbent third baseman who signed a 10-year, $313.5 million contract extension just two years ago, refused to rule out a trade demand if the team attempts to play Bregman at third base.

In his first public comments since the end of last season, when he was shut down on Sept. 21 due to a shoulder injury, Devers was asked whether he would accept a move to designated hitter to make way for Bregman, who won the American League Gold Glove award for his work with the Houston Astros at the hot corner in 2024.

Devers had a short and definitive one-word answer to the question: “No.”

He also said that when he signed his long-term contract extension before the 2023 season, the Red Sox promised him the third base position was his, adding that he was was disappointed in the team for apparently going back on its word.

Told about Devers’s remarks, manager Alex Cora simply replied, “Chaim is in St. Louis.”

That was a reference to Chaim Bloom, the Red Sox chief baseball officer who signed Devers to the extension. But Bloom was fired in September 2023. The 41-year-old Bloom was hired a year later to work in the St. Louis Cardinals’ front office, and according to the team will take over as president of baseball operations after the 2025 season.

For Red Sox fans, and presumably the organization, the most alarming remarks to come out off Devers’ mouth on Monday came when he refused to rule out a trade demand if the Red Sox insist on giving the third base job to Bregman.

“That’s a tough answer to give. I haven’t given it much thought,” Devers said, responding to a media question about a trade demand. “I’ve been here my entire career. I haven’t asked myself that question. I’m open to listening. I’m not close to those conversations.”

The 30-year-old ex-Astro was seen taking infield practice at third base on Sunday, while Devers took his reps indoors.

• Red Sox Rumors: Why Boston Still Hasn’t Decided On Alex Bregman’s Position

Bregman has been a significantly better third baseman than Devers, according to Fangraphs’ advanced fielding statistics. In the “defensive runs saved” metric, a measure of how many opponent’s runs above (or below) average a fielder prevented, Bregman over nine years has saved 27 runs.

But in his eight-year career, Devers has a negative number in that category of -62. using baseball’s statistical “rule of thumb,” holding that every 10 runs equals one win, the 89-run difference means that Bregman’s teams have won nearly nine more games than Devers’ teams over their careers, simply due to the difference in the two players’ third base fielding performance.