Horton will undergo an exam on his right shoulder in mid-November in hopes of gaining clearance to begin a throwing program, Meghan Montemurro of the Chicago Tribune reports.

Horton recently suffered a setback in his rehab for a right lat strain and isn't expected to return from Triple-A Iowa's 60-day injured list this season, Tim Stebbins of MLB.com reports.

Horton (lat) was diagnosed with a subscapular strain Tuesday and will be shut down from throwing for 3-to-4 weeks, Tony Andracki of Marquee Sports Network reports.

Horton had to be removed from a start with Triple-A Iowa on Wednesday due to right lat soreness, Maddie Lee of the Chicago Sun-Times reports.

Horton averaged 93.4 mph (touched 94.9 mph) with his fastball in his first start for Triple-A Iowa on May 4 and averaged 93.9 mph (touched 95.5 mph) in his second start May 10 after sitting at 95-97 mph with his fastball and regularly touching 98 mph in 2023.

Horton has been promoted from Double-A Tennessee to Triple-A Iowa, Tommy Birch of the Des Moines Register reports.