Mitch Moreland was leading the Red Sox in batting average, home runs and RBI before Boston traded him to San Diego on Sunday for two prospects. Winslow Townson/Associated Press

Mitch Moreland was one of the most popular players on the Red Sox, a veteran with an upbeat personality who connected with the people around him in the clubhouse and in the community.

He was also one of Boston’s best players in 2020. When he was traded to the San Diego Padres on Sunday morning he was leading the team with eight homers, 21 RBI and a .328 batting average.

Now he’s gone, a stark reminder that popularity doesn’t factor into the evaluation of a team. The Red Sox are building for the future and a player excelling in the present is a sought-after commodity for teams in the hunt for a playoff spot.

Two other members of the Red Sox were dealt shortly before Monday’s trade deadline: Outfielder Kevin Pillar to Colorado and pitcher Josh Osich to the Cubs, both for players to be named later.

The trades are a price a team pays for playing bad baseball. The defending champs were a disappointment last year and the team has slid all the way down to last place in 2020.

Chaim Bloom got two young prospects in return for Moreland. They aren’t being brought into help the Sox compete in 2021. They’re coming over for the long-term, helping restock a minor-league system that was stripped down to win a championship.

What will help the team compete sooner is getting under Major League Baseball’s competitive balance tax threshold. Tuesday is an important day in that quest. Had the season been canceled before September, the team’s CBT status would’ve reset to last year. That would’ve meant the Sox would be back in the heavily taxed category.

We got a reminder just how close to not reaching September baseball has been when yet another game was postponed because of a COVID-19 case. The A’s game in Houston on Sunday was postponed when Oakland received a positive test. There has only been one day in the past five weeks that all 30 teams have played.

By getting under the tax threshold, the Red Sox will have more money available to spend to build a more competitive team in 2021 and beyond. Team ownership has stated all along that resetting the tax was a goal, not a mandate. Yet the trade of Mookie Betts and David Price to the Dodgers in February was a clear sign they were shedding payroll in an effort to reset.

In the meantime, we are left to read the tea leaves as we try to see how long this rebuilding process will take. The take for Moreland wasn’t about the short-term future. An earlier trade sending Brandon Workman and Heath Hembree to Philadelphia brought back two pitchers who will be here much sooner than that.

Fans around here won’t have much patience for a long-term overhaul. Not after a 2020 season in which the Red Sox are losing at a historic clip. When they lost the opener of the series with Washington on Friday they fell to 10-22, their worst record after the first 32 games of a season since 1932.

So it should come as no surprise that no one was safe as Bloom sorted through offers in the final hours before the deadline. Moreland delivered one of the biggest home runs in franchise history, a pinch-hit, three-run homer that triggered a comeback at Dodger Stadium in Game 4 of the 2018 World Series.

Now he’s headed back to California. And we’re reminded that 2018 was a long time ago.

Tom Caron is a studio host for Red Sox broadcasts on NESN.