How good is the 2026 Red Sox starting pitching depth?

Welcome back to our preview of 2026 Red Sox starting pitching. If you missed the bulk of the preview last week, check it out below.

Today, we turn our attention to the back of the back of the rotation: the depth starters.

Now that we’ve been through the nine pitchers who are fighting for spots in the opening day rotation, we can turn our attention to the depth. In theory, those nine arms I already went through will make the bulk of the starts for the Red Sox this season. This is major league baseball we’re talking about, though, and pitching injuries are bound to happen. Last season, 15 different pitchers started games for the Red Sox, and Brennan Bernardino was the only true “opener” they used. Come August, when the rotation has been through the wringer and is run down, look for one of these names to provide five innings or so.

Tyler Uberstine

Of the options on this list, Tyler Uberstine is probably first in line to make a spot start, although there are several pitchers ahead of him (covered here and here).

Uberstine, who reached Triple-A last season, was added to the 40-man roster to protect him from the Rule 5 Draft this winter. Like many Red Sox pitchers, he has a low release point that creates a flat approach angle for his mid-90s fastball. Over about 90 innings at Worcester, he struck out a very respectable 26% of hitters, but struggled with walks, handing out free passes at a 9.4% clip. He uses multiple breaking balls, with his slider and changeup showing the most potential. His ceiling is likely a back-of-the-rotation arm, but there’s nothing wrong with eating innings to help carry the load through a very long season.

Jake Bennett

Jake Bennett is 6’6”, 235 pounds and throws with his left hand. He has seven feet of extension. In his first Spring Training outing, his fastball averaged 95 mph and reached 98 mph. According to SoxProspects, he has “advanced command and control” of said fastball.

My scouting report is based on the numbers and other people’s scouting reports, but I’m buying all the Jake Bennett stock I can get. His best secondary pitch is a changeup, which will neutralize righties, while he also has a slider and a curveball. He’ll mix in sinkers and cutters to fill up the zone, and has a slider and a curveball as well. That’s six pitches from a huge lefty who gets down the mound well. He’s at least a back-of-the-rotation arm with a chance to be much more.

While there’s a long list of pitchers ahead of him for turns in the rotation, I wouldn’t be shocked to see Bennett knocking on the door of the majors for some leverage relief appearances late in the season. He’s the pitching prospect I’m most excited about.

Kyson Witherspoon

After the ascent of Payton Tolle and Trey Yesavage, flying through the minor leagues is all the rage. As such, many have tabbed 2025 first-round pick Kyson Witherspoon to debut a year after being drafted, despite not pitching in the minor leagues in 2025.

He has a huge fastball that’s already up to 97 mph in camp, along with a cutter and slider that he executes consistently. Fangraphs labeled his curveball and changeup as his nastiest pitches, but said they need polish to be viable weapons. His high 70s curveball was described as “hitter-pantsing” when thrown in the dirt. Because there are so many names ahead of him on the depth chart, I’m going to guess Witherspoon debuts in mid-2027, but crazier things have happened, and he’s a fun name to monitor going forward.

Tanner Houck

Houck is the only guy on this list that we’ve seen in action before, but he’s last because we won’t see him until September, if at all. He had Tommy John Surgery last season after an ugly start to his campaign. He threw a baseball for the first time this spring, but is still a long way from returning to game action.

While he might fill some innings down the stretch, don’t expect Houck to become a key contributor. At his best, Houck is in the zone with everything he throws, keeping hitters on the back foot. His splitter is particularly important against left-handed hitters, and while it’s somewhat of an anecdote, finding a feel for offspeed and breaking pitches seems to lag behind fastballs when returning from TJS. I can’t support that evidence, but I feel like James Paxton said it once, and I’ve taken it as gospel. If Houck returns in 2026, I wouldn’t be surprised to see him in a relief role with a focus on returning to the rotation in 2027.