Joely Rodriguez, who pitched for the Mets last season, is scheduled to make an appearance for the Sea Dogs on Saturday and could be called up to Boston on Monday. Adam Hunger/Associated Press

Joely Rodríguez will make his third appearance for the Portland Sea Dogs on Saturday, and could be activated before Monday’s series opener against the Seattle Mariners.
The left-handed reliever was Boston’s first free agent signing last November, but hasn’t pitched for the big-league team yet. He began the season on the injured list, after suffering a right oblique strain during a spring training game.

Rodriguez has pitched twice for Portland this week, pitching a scoreless inning on both Tuesday and Wednesday.

Rodríguez last pitched for the New York Mets. In 2022, he posted a 4.47 ERA across a career-high 55 games, including nine games finished. He ranked in the 84th MLB percentile or better in expected slugging (84), hard hit rate (91), chase rate (94), barrel rate (95) and average exit velocity (96). He struck out 57 batters and only gave up three home runs, but also issued a career-worst 26 walks, putting him in the sixth percentile in walk rate.

Upgrading the bullpen was one of Boston’s top priorities over the offseason, and despite some dicey moments, the extreme makeover is paying off. Red Sox relievers collectively own a 3.42 ERA and are holding opposing batters to a .236 batting average, over 144.2 innings, which is tied for third-most in the American League. The Red Sox are 14-3 when they score first, and are 16-0 when leading after six innings, and undefeated when they lead after the sixth (16-0), seventh (17-0) and eighth innings (19-0).

Garrett Whitlock will pitch for Triple-A Worcester on Tuesday. A bullpen standout in his 2021 debut season, the Red Sox now view him as a starting pitcher. He was placed on the injured list in late April with ulnar neuritis, but tests revealed no ulnar nerve damage.

THE TAMPA BAY RAYS claimed Zack Littell off waivers, a week after the Red Sox acquired him from the Texas Rangers for cash considerations.

In between, the 27-year-old right-hander made a pair of relief appearances for the Red Sox. He allowed three earned runs on three hits, three walks plus one intentional, and struck out two across three innings.

Littell becomes the second former Red Sox reliever to join the Rays this week for pennies on the dollar. They also signed Jake Diekman to a major league deal on Tuesday, after the left-hander was released by the Chicago White Sox.

Diekman signed a two-year, $8 million contract with the Red Sox ahead of the 2022 season, but struggled during his time in Boston, posting a 4.23 ERA across 44 games. While he struck out 51 batters across 38 1/3 innings, he also allowed 22 runs, 18 of them earned, on 27 hits, issued 30 walks.

The Red Sox traded Diekman to the White Sox at the deadline, at which time Chicago took on the remainder of his contract, which includes a $4 million club option or $1 million buyout for next year. As such, the Rays will only pay the lefty the prorated major league minimum.

Tampa Bay’s bullpen has the third-best ERA in the majors, and a tendency to turn other teams’ discards into dominant arms. Will they strike gold again with Littell and Diekman?