The Kansas City Chiefs have placed linebacker Cooper McDonald on injured reserve after he suffered a knee injury during Monday night's 31-10 Week 1 victory over the Denver Broncos.

NFL Network's Jordan Schultz reported the move Wednesday, adding that McDonald is expected to return at some point this season.

“#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.

“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.

McDonald is a former UDFA who made the team in 2025 and has become a locker-room favorite. pic.twitter.com/B2MQrkDzjX

— Jordan Schultz (@Schultz_Report) September 16, 2026

McDonald's move to injured reserve creates an early setback for the Chiefs' linebacker depth following their dominant season-opening performance. The former undrafted free agent earned a spot with Kansas City in 2025 and has since carved out a role with the team.

While McDonald will miss time, the expectation that he can return this season provides some optimism for Kansas City as it moves forward with its schedule.

The Chiefs opened the season with a convincing performance against the Broncos, scoring 31 points while holding their AFC West rival to 10.

Kansas City will now turn its attention to its Week 2 matchup against the Indianapolis Colts, who enter the game at 0-1. The Chiefs will host the Colts on Sunday at 8:20 p.m. ET on NBC.