ENGLEWOOD, Colo. — Inside linebacker Corey Nelson suffered an elbow injury during Thursday's practice and will be placed on injured reserve, Head Coach Vance Joseph announced Friday.

"Corey's had a great year, both on defense and special teams," Joseph said. "That's a big loss for us, but it happens."

Nelson will have season-ending surgery on Monday, and the Broncos will bring up practice-squad linebacker Jerrol Garcia-Williams.

Joseph also announced tackle Donald Stephenson will miss Sunday's game with a lower-calf injury he suffered during Sunday's practice. Stephenson was an option to fill in at right tackle for Menelik Watson, who is out for this weekend's game.

"[Stephenson has] probably a week-to-week injury, to be honest with you," Joseph said. "It's a small tear in the lower calf. He's had it before, and it was a couple weeks, so it'll be week to week."

Joseph said he hoped Watson will be healthy enough to play against the Kansas City Chiefs in Week 8, but he will be evaluated next week. Watson suffered a calf injury against the New York Giants and has been listed as day to day.

Allen Barbre will start at right tackle in place of Watson.

Joseph said the Broncos will make an additional roster move along the offensive line to bring the active roster to 53.

"You guys seem more worried than I am," Joseph said. "Don't worry. We're going to kick the ball off and play."

Quarterback Paxton Lynch and wide receivers Cody Latimer, Isaiah McKenzie and Emmanuel Sanders are also out for the Broncos' game against the Chargers.

Wide receiver Demaryius Thomas and linebacker Brandon Marshall were both cleared to play in Sunday's game.