The Pablo Sandoval era is over in Boston.

Sandoval was informed Friday that he has been designated for assignment, the Red Sox announced, a move effectively terminates one of the worst free-agent signings in franchise history. The Red Sox still owe the 30-year-old third baseman approximately $49 million through the end of the 2019 season.

Boston has 10 days to either trade or release Sandoval.

"I thank the Boston Red Sox for the opportunity and I remain positive that with the love and support of my family I will continue on with my career," Sandoval told ESPN's Marly Rivera.

Sandoval said he is currently in Miami, where he will remain training and working out, preparing for the next step in his career.

The Red Sox signed Sandoval to a five-year, $95 million contract after the 2014 season. He was coming off a stellar postseason and a third World Series title with the San Francisco Giants and was pursued aggressively by both the Giants and the San Diego Padres.

But Sandoval's tenure with the Red Sox was characterized by poor performance, multiple injuries and frustration by the team over his subpar conditioning. In 161 games for the Sox, he batted .237 with 14 home runs, 59 RBIs, a .646 OPS and 21 errors at third base. Sandoval was worth two wins less than the value of a replacement player, according to Baseball-Reference.com.

Sandoval spent the past two weeks on a minor league rehab assignment with Triple-A Pawtucket after going on the disabled list with an inner-ear infection. During that time, the Red Sox got surprisingly strong performances at third base from light-hitting Deven Marrero and Double-A call-up Tzu-Wei Lin. With Sandoval nearing the end of the maximum 20-day assignment, the team was forced to make a decision.

"It really came down to us feeling that we were not a better club if he was on our club at the major league level," president of baseball operations Dave Dombrowski said. "It was a tough decision, but it was one that we felt was the right one."

Sandoval is due more money than the combined $47.3 million the team's top nine players, per WAR, combined will make this season: outfielder Mookie Betts ($950,000); pitcher Chris Sale ($12 million); outfielder Jackie Bradley Jr. ($3.6 million); closer Craig Kimbrel ($13 million); shortstop Xander Bogaerts ($4.5 million); pitcher Drew Pomeranz ($4.45 million); reliever Joe Kelly ($2.8 million); first baseman Mitch Moreland ($5.5 million); and outfielder Andrew Benintendi ($549,000).

After missing almost all of last season while recovering from shoulder surgery, Sandoval had virtually no competition for the third base job in spring training. The Red Sox traded Travis Shaw, who beat out Sandoval for the position before last season, to the Milwaukee Brewers for reliever Tyler Thornburg, who won't throw a pitch this season after undergoing surgery for thoracic-outlet syndrome.

Sandoval has played only 32 games this season, batting .212 with four homers, a .622 OPS and five errors.