The Kansas City Chiefs‘ initial injury outlook on Wednesday was generally good, as Mansoor Delane was on the practice field. However, the team had an unfortunate update to share on linebacker Cooper McDonald.
NFL insider Jordan Schultz broke the news via X on September 16 that McDonald will miss at least four weeks on injured reserve (IR).
McDonald is a former UDFA who made the team in 2025 and has become a locker-room favorite.
“#Chiefs LB Cooper McDonald will be placed on IR due to a knee injury he suffered during Monday night’s win over the Broncos. He is expected to return this season,” Schultz wrote. “McDonald is a former UDFA who made the team in 2025 and has become a locker-room favorite.”
Head coach Andy Reid confirmed the McDonald news during his press conference Wednesday.
McDonald appeared in all 17 of Kansas City’s games as rookie, earning one start. He was mostly a special teams player, logging 289 snaps in that phase of the game along with 57 defensive snaps in 2025. He finished last season with 25 combined tackles, including one tackle for loss.
The second-year linebacker played just two snaps on special teams against Denver on Monday night before suffering his injury.
Mansoor Delane Back at Chiefs Practice After Shoulder Injury
Meanwhile, the news on Delane was incredible, as he returned to work Wednesday just two days after leaving the game against the Broncos with an injury to the same shoulder that sidelined him for significant time during training camp and the preseason.
“Mansoor Delane will practice today,” Sam McDowell of the Kansas City Star reported. “Josh Simmons and Chamarri Conner won’t practice. Andy Reid said both are making progress.”
Reid added in his media availability that there is a reasonable chance Delane will play against the Indianapolis Colts on Sunday, September 20.
The first-round cornerback (No. 6 overall) made an interception during the first coverage snap of his NFL career. However, he landed awkwardly on his shoulder following the INT and ultimately did not return for the remainder of the game.
Delane underwent successful tests over the past 36 hours or so, which indicates that he suffered a sprain of the shoulder in the worst-case scenario. That he is back on the practice field already is an excellent sign for the trajectory of his rookie campaign.
Chiefs Left Tackle Josh Simmons Still Sidelined With Back Injury
Simmons’ absence from practice after missing Week 1 is the next biggest bit of injury news coming out of Kansas City mid-week.
The 2025 first-round pick is the starting left tackle when healthy, though undrafted rookie Khalil Benson, who was in a dog fight for the right tackle spot throughout camp, stepped in and afforded zero pressures to the vaunted Broncos defense in his debut.
All told, the Chiefs’ rookie class was impressive on the big stage Monday night, as second-round edge-rusher R Mason Thomas also logged a sack in his first game.
How the group plays in Week 2 against a gettable opponent in the Colts during their encore performance should provide interesting data for season-long projections of success moving forward.
Chiefs Share Rough Injury News on ‘Locker Room Favorite’ After Delane’s Return