ENGLEWOOD, Colo. — The clock might be ticking down on Brandon McManus’ time in Denver.

After the first-year kicker missed a 33-yard field-goal attempt in the third quarter Sunday to drop to a league-worst 9-of-13 on his attempts this season, the Broncos lined up veterans Connor Barth and Jay Feely for tryouts at team headquarters on Tuesday.

Broncos coach John Fox downplayed the reports that the Broncos wanted a new kicker.

“There is no search for a new kicker. We have tryouts every week at a lot of different positions,” he said. “My satisfaction with Brandon is kind of like our record. We’re 8-3. I wish we were 11-0 but we are where we are and we’re always looking to improve our team if we feel we need to be.”

But the anguished reactions of guard Manny Ramirez and wide receiver Demaryius Thomas after McManus’ attempt slammed into the right upright revealed a team losing confidence in its kicker, and perhaps unwilling to ride out a slump as he develops.

“We’re a performance-based business and regardless of what your job description is you’re expected to perform,” said Fox. “I don’t think he is the worst kicker in the league by any stretch.”

— The Broncos might be without their best, open-space run defender when they visit the Kansas City Chiefs’ potent ground game Sunday.

Weakside linebacker Brandon Marshall, the Broncos’ leader in tackles after replacing the injured Danny Trevathan, left Sunday’s game late with a concussion and will go through the league-mandated protocol to determine when he can return.

Denver’s linebacker corps is already decimated by injuries. Trevathan hasn’t played since Week 6 because of a crack above his knee and cannot return to game action until Week 15. Middle linebacker Nate Irving was lost for the season due to a knee injury in Week 10.

Since Irving’s injury, the Broncos have made extensive use of safety T.J. Ward as a linebacker in the box when they go into a nickel alignment.

“It’s shared coaching,” Fox said. “He can be with (linebackers coach) Richard Smith or be with [secondary coaches] Sam Garnes or Cory Undlin. Von Miller is the same way; he’s a linebacker on early downs, and he’s an end on some third-down stuff.

“It takes a unique player to do those things. T.J., with some of the injuries we’ve had, has stepped in and executed that role pretty well.”

The Broncos could expand Ward’s role to every-down if Marshall can’t play. But then that would leave one of three rookies — Lamin Barrow, Corey Nelson or Todd Davis — to play the other spot. Another option would be to use current starting linebacker Steven Johnson in the nickel.

“I’m hoping for Brandon to be healthy, because we definitely need him,” cornerback Chris Harris Jr. said. “This game is going to be a lot of base (defense), so we expect them to try to come out and run the ball. We’re going to need all our linebackers this game. It’s pivotal this week.”

Notes: Wide receiver Emmanuel Sanders completed the post-concussion protocol in time to play Sunday and finished with a team-leading 125 yards on nine receptions. … CB Aqib Talib suffered a strained hamstring in the first quarter and will be considered “day-to-day” this week. … RB Montee Ball (groin) will be watched carefully after an extended absence with the same injury previously.