ENGLEWOOD, Colo. – With the salary cap already low, the Denver Broncos decided this week which pending free agent outside linebacker they could retain.

The Broncos have signed Jonathon Cooper to a four-year contract extension, the team announced Monday. Financial details were not disclosed, but a source told ESPN's Adam Schefter that the extension was worth $60 million with $33 million guaranteed.

Cooper has been called one of the team's top performers by coach Sean Payton and is second on the team with 5.5 sacks, just behind Nik Bonitto's six. The Broncos, who are second in the league with 31 sacks, have had 12 players with at least half a sack through the first nine games.

Cooper, a seventh-round pick by the Broncos in the 2021 draft, was on the verge of becoming an unrestricted free agent in March, as was fellow outside linebacker Baron Browning, a third-round pick that same year. The Broncos decided to sign Cooper over the weekend and trade Browning to the Arizona Cardinals on Monday for a 2025 sixth-round pick.

Cooper led the team with 8.5 last season. He has played in 56 games over the last four seasons, including 40 starts, although his time with the Broncos began with medical uncertainties.

The Broncos knew Cooper had been diagnosed with an irregular heartbeat in high school. Doctors later said it was Wolff-Parkinson-White syndrome, a congenital heart defect that causes irregular or rapid heartbeat.

Cooper had two ablations in high school, procedures in which catheters are passed through blood vessels to the heart while the tissue in the heart is then scarred to block abnormal electrical signals and restore a normal heartbeat. He then played the rest of his prep career and five seasons at Ohio State without problems.

However, during medical exams leading up to the 2021 NFL Draft, it was determined that Cooper required another ablation. He said he received the news about 48 hours before the first round.

Shortly after joining the Broncos, he had three separate eight-hour procedures and missed part of the team's offseason program that year before being medically cleared and playing in 16 games as a rookie.