Jonathan Cannon

The White Sox announced Tuesday that righty Jonathan Cannon has been placed on the 15-day injured list due to a lower back strain. Right-hander Caleb Freeman is up from Triple-A Charlotte to take Cannon’s spot on the active roster.

Cannon, 24, was sharp through his first nine trips to the hill this season (3.60 ERA, 18 K%, 7.8 BB% in 50 innings) but has run into a rough patch of late. Over his past trips to the mound, he’s been roughed up for 13 runs on 17 hits and four walks in 13 2/3 innings. Yesterday’s outing against the Tigers was particularly shaky; Cannon surrendered five runs — on the strength of three homers — and walked three batters in just three innings. A recent velocity drop could underscore the fact that he’s been pitching at less than 100 percent; Cannon averaged 93.5 mph on his four-seamer and 93 mph on his sinker through May 18 but has averaged just 91.8 mph and 92 mph, respectively, since.

The South Siders haven’t yet said how long Cannon will be out. Bruce Levine of 670 The Score reports that the Sox have already had imaging performed but have not yet publicly disclosed the results. It’s also not clear who’ll replace Cannon in the rotation. The Sox are currently going with Shane Smith, Davis Martin, Sean Burke and Adrian Houser in an all-righty rotation. Swingman Bryse Wilson is stretched out enough that he tossed five innings yesterday in relief of Cannon, but he’s sitting on a 6.80 ERA this year — including 17 earned runs in his past 14 2/3 innings.

Chicago’s depth chart has thinned out in recent months. Prospects Ky Bush and Drew Thorpe are out for the season after undergoing Tommy John surgery this spring. Other once-well-regarded prospects like Jairo Iriarte, Nick Nastrini, Owen White and Wikelman González have all struggled in the upper minors. Veteran southpaw Martín Pérez is out until at least September and could miss the rest of the year due to a flexor strain.

Lefties Noah Schultz and Hagen Smith are two of the top pitching prospects in all of baseball, but neither has even reached Triple-A yet; Smith only has 25 Double-A frames under his belt. The Sox probably want both to get more development time in before bringing them to the majors — particularly since neither needs to be added to the 40-man roster this offseason in order to be protected from the Rule 5 Draft.

The South Siders do have a top prospect who’s making a compelling case for a call to the majors sooner than later, but it’s not one of their coveted young arms. Catcher Kyle Teel, the headline prospect in the trade sending Garrett Crochet to Boston, is hitting .289/.394/.491 in Triple-A (131 wRC+). Teel has walked in a massive 14.8% of his plate appearances, fanned at a 26.6% clip that the Sox would surely like to bring down, clubbed eight homers and even swiped seven bags in eight attempts.

A consensus top-50 prospect in the sport, Teel got out to a slow start this season but has only been held hitless four times in 34 games dating back to an April 12 doubleheader where he went 0-for-3 in both halves of that twin bill. In 134 plate appearances since that time, the 2023 first-rounder (No. 14 overall) is batting .331/.428/.532. Strikeouts remain an issue, and Teel’s .378 average on balls in play isn’t sustainable, but it’s hard for him to do much more to clamor for a call to the majors.

The Sox, it seems, are taking notice. Teel tells Scott Merkin of MLB.com that the organization has begun to have him work out at first base. Teel hasn’t played there in a game yet but has been taking grounders at first base the past few days and working with the staff in Charlotte to acclimate himself to a new position.

Chicago recently optioned longtime first baseman Andrew Vaughn to Charlotte. The former No. 3 pick has been a constant in their lineup for four-plus seasons but has never lived up to expectations when he was one of the top prospects in his draft class. Vaughn has been a roughly average offensive performer with poor glovework and baserunning. The Sox are surely hoping he can get on track in Triple-A and salvage some value later this summer, but sending him down and getting Teel some looks at first base signal a clear shift in the team’s plans.

Teel probably isn’t an option to be the Sox’ everyday first baseman moving forward. He’s regarded as a viable defensive catcher who blocks balls in the dirt and throws well. He’s nabbed 33% of would-be base thieves this season. Baseball Prospectus also gives him solid framing marks behind the dish in the minors.

That said, the Sox entered 2025 with two of baseball’s top catching prospects: Teel and former minor league teammate Edgar Quero. It was Quero who received the first call to the majors, and he’s held his own, hitting .248/.336/.301. That’s about 13% worse than league-average overall, per wRC+, but not far off the average line posted by catchers in 2025. Quero has walked in 10.2% of his plate appearances against a 16.4% strikeout rate that’s about six percentage points better than average. He’s also making plenty of hard contact, but too much of it is resulting in grounders rather than line-drives or fly-balls. For a player whose sprint speed ranks in just the seventh percentile of MLB hitters, per Statcast, that’s not a good batted-ball trait.

Quero started quite strong and had a league-average batting line as deep into the season as May 25, so it’s not as if he’s been a lost cause at the plate. He’s in the midst of a dreadful 6-for-38 stretch, but he’d hit well prior to this slump. A cold streak spanning all of two to three weeks isn’t going to change the organization’s long-term view of Quero. The Sox are still hopeful that Quero and Teel can be their catching tandem for the next several years, and Teel getting some reps at first base only makes it easier for the Sox to get both into the lineup — assuming Teel handles the drills at first base reasonably well.