While the two teams only face each other once a year, the players acquired in return for the designated hitter will be held to high standards as they begin their Red Sox tenures. Left-handed pitcher Kyle Harrison is up to the task and has already begun working to improve.

Harrison is currently in Triple-A Worcester; he’s thrown bullpen sessions and faced live hitters, but has yet to appear in a game. The lefty is slated to make his first start for the organization on Thursday, where he’ll try to implement the new pitches he’s been working on.

Harrison currently throws a four-seam, curveball and changeup. The four-seam has all the qualities of an excellent major league fastball, but the rest of his arsenal could use some work. The curveball is a slow, sweepy curveball that doesn’t quite play off the fastball correctly. The changeup has been inconsistent, but it flashed serious potential in his most recent major league outing.

The southpaw has reverse platoon splits and could take his game to the next level by tweaking his arsenal. He’s reportedly working on a sinker and a cutter, each of which should assist in that mission.

If Harrison can create good separation from his four-seamer with his sinker, it should work as a pitch to throw on the arm-side to jam lefties and earn strikes. A cutter or hard slider, depending on the shape, should work to induce whiffs on the glove side.

If he can implement these tweaks, his arsenal may look similar to Brayan Bello’s, but from the left side. Harrison uses a four-seam primarily, though, so he should miss more bats. It’s also not dissimilar from the Phillies’ Christopher Sanchez, who uses a sinker, changeup, and slider from a low, left-handed slot to keep hitters off balance.

Harrison hasn’t even made an appearance yet, so the pitches may still need some work. Still, his willingness to embrace these tweaks is a great sign for a young pitcher.