Boston Red Sox owner John Henry explained his team's unpopular trade of Mookie Betts in an open letter to fans Monday.

The Red Sox traded away Betts and David Price to the Los Angeles Dodgers in a deal that returned Alex Verdugo and two prospects.

In the letter, Henry compared Betts' departure to other popular players like Nomar Garciaparra, Pedro Martinez and Manny Ramirez.

"We no longer live in the Musial or Williams era," he wrote, referencing Stan Musial and Ted Williams, who played their entire careers with one organization.

Betts is set to enter free agency next offseason, and the Red Sox decided to make a trade now rather than lose him next winter.

"We felt we could not sit on our hands and lose him next offseason without getting value in return to help us on our path forward," Henry said in the statement.

The 27-year-old will almost certainly command a huge salary on the open market after earning four All-Star selections, four Gold Glove Awards and an MVP Award in the past four years. He's proved to be one of the top two-way players in the sport and should improve upon his $27 million salary from this season.

The Red Sox haven't been shy about handing out big contracts in the past, spending more than $100 million on contracts for J.D. Martinez, Xander Bogaerts and David Price, also trading for the high-priced Chris Sale.

However, the organization appeared to shift strategies this offseason while focusing on reducing payroll.

"We need to be under the [Competitive Balance Tax]," Henry said in September, via the Associated Press (h/t ESPN). "That was something we've known for more than a year now."

It meant the Red Sox not only wouldn't pursue Betts as a free agent, but they also used the deal to clear his and Price's salary for 2020.

Even with Henry's letter justifying the trade, Boston fans will likely remain upset for some time.