What can Red Sox get out of latest waiver claim from Royals?

The Red Sox offseason work on their rotation is in full swing. After trading seven-time All-Star Chris Sale and signing veteran right-hander Lucas Giolito, Boston has hit the waiver wire.

The Red Sox claimed right-handed pitcher Max Castillo from the Kansas City Royals on Tuesday night.

The 24-year-old Venezuelan made his major league debut in 2022, but spent the majority of the 2023 season with Triple-A Omaha. He made 22 appearances for the club (21 as a starter) and he finished the season 6-7 with a 4.58 ERA and 94 strikeouts over 116 innings.

Castillo clocked seven MLB appearances in 2023, all out of Kansas City's bullpen. He allowed 10 runs in his 20.1 innings pitched (good for a 4.43 ERA) while striking out 10 in the big leagues.

What can the Red Sox get out of former Royals pitcher Max Castillo?

Castillo was designated for assignment by the Royals in late December and the Sox signed him during an extended window due to the holiday break. The 24-year-old took the final open spot on the Sox's 40-man roster before the deal with Giolito was finalized on Wednesday afternoon (which saw Mauricio Llovera was DFA'd to make room for the veteran). And with other needs still on the table for the Sox's offseason, such as a reliable middle infielder, the addition of Castillo gives the impression that more changes are on the way.

Castillo will likely be a depth piece for the team and remain in Worcester until he's needed at Fenway. And with Boston's injury-prone and stressed rotation, that time could come sooner than anyone might expect. But the WooSox need a reliable starter, too, and Castillo, an accurate right-hander, could prove to be just that. He has a fastball, slider and changeup arsenal that could profile very well as a multi-inning reliever out of the bullpen. He averages 93 MPH on his four-seamer, 87 MPH on his changeup and 84 MPH on his slider.

Castillo has both starting and relief pitching experience, which fits him well with the Red Sox in their current state. The rotation and bullpen are uncertain now, and there could be a lot of change within the next few years. Nick Pivetta, another flexible asset, will be a free agent at the end of the upcoming season, while Giolito can opt-out after this year. If Castillo improves in Triple-A or makes any positive appearances in the majors for the Sox, he could become an inexpensive bullpen option for the future.