BOSTON -- It’s time for the Red Sox to cut their losses with Tyler Thornburg.

Just about the only negative in Boston’s 5-1 win over the Athletics on Tuesday night was the performance of Thornburg, who entered with a 5-0 lead in the ninth and promptly allowed a leadoff homer to Robbie Grossman. Though Thornburg worked around a walk to end the ballgame without any more trouble, the outing was yet another example of his inability to deliver a clean inning, even with nothing on the line.

Nine of Thornburg’s 11 appearances this year have come in spots where the Sox were either leading or trailing by more than three runs and his two most recent outings have come with Boston leading by 10 and five runs, respectively. Even in those low-leverage situations, Thornburg has allowed at least one run in five outings and has a bullpen-high 7.71 ERA.

Thornburg, who was acquired in the ill-fated trade that sent infielder Travis Shaw and two prospects to the Brewers in 2016, spent a year and a half rehabbing from thoracic outlet syndrome surgery before making his Red Sox debut in July. He struggled to a 5.63 ERA in 25 low-pressure appearances for a Sox team that had little to play for down the stretch, was shut down in mid-September and was not considered for the postseason roster.

After re-signing Thornburg to a non-guaranteed, $1.75 million deal over the winter, the Sox were impressed enough by what they saw in spring training to give him a spot on the Opening Day roster despite his 9.45 ERA in seven outings. That decision guaranteed Thornburg’s contract and extended his leash with the organization even longer instead of having him be exposed to other clubs via waivers.

Thornburg is now fully healthy, with his velocity and mechanics both indicating his shoulder issues are behind him. But the results haven’t been there, as he has been hit hard all season while falling behind every other Sox reliever on the depth chart.

The Red Sox gave Thornburg a year and a half to get healthy and a half-season to get re-acclimated to the majors before asking him to prove his worth in 2019. The lack of experienced options on the Opening Day bullpen likely played into the team’s decision to keep him, but it has become clear after one month that there are pitchers more deserving of a spot.

There’s a case to be made that Travis Lakins, Bobby Poyner and Jenrry Mejia should be on the roster over Thornburg, and that’s on a team with two extra spots due to injuries to Brian Johnson and Nathan Eovaldi. When those two come back, the staff will be even more crowded.

Dave Dombrowski has given Thornburg an extremely long leash with virtually no return on the significant investment he made in 2016. But he need not worry about optics at this point, as Shaw’s strong 2017 season with the Brewers won the trade for Milwaukee long before Thornburg even entered a real game for the Red Sox.

Thornburg’s Red Sox career was doomed from the beginning due to injuries and he should be credited for being nothing but accountable and honest throughout a prolonged tough stretch in his career. But it’s clear now that the Sox don’t trust Thornburg enough to put him in any meaningful situations, making his roster spot seem like a wasted one.

Maybe a change of scenery will help Thornburg resurrect a career that had tons of promise in his last year with the Brewers. It’s time for the Red Sox to recognize that he’ll never get to that point in Boston.