As Sports Authority unravels in bankruptcy, so does its role as a key sponsor of the Denver Broncos.

The clock is ticking on the Englewood-based Sports Authority’s sponsorship contract with the team, according to documents filed Friday in the U.S. Bankruptcy Court in Delaware.

A quarterly payment of $1.053 million was due May 1, part of a 2011 agreement that bundles Mile High Stadium naming rights with a broader sponsorship arrangement.

A missed payment could eventually trigger a termination of a contract that has Sports Authority on the hook for a total of $36 million through 2035.

“Remember, Sports Authority was a team partner for many years before acquiring the naming rights to the stadium,” Broncos spokesman Patrick Smyth said in an e-mail to the Denver Post. “We’re aware of the developments in bankruptcy court, and we continue to monitor them and stay in communication with Sports Authority as well as the Metropolitan Football Stadium District.”

Friday’s bankruptcy documents — filed by the Broncos in response to Sports Authority’s attempts to cure and eventually sell or assign contracts — provide the first glimpse of the multimillion-dollar pact.

When Sports Authority assumed the remainder of a $120 million Mile High naming-rights agreement vacated by Invesco Ltd. in 2011, the payments graduating from $6 million to $9 million a year were split between the public Metropolitan Football Stadium District and the Denver Broncos, which did not disclose its contract or terms.

Sports Authority owes the stadium district $19.95 million — including a $3.6 million payment due Aug. 1 — through 2020.

The team and the district have been in a wait-and-see mode since Sports Authority filed for Chapter 11. Marketing experts have said the naming-rights deals could be well worth maintaining — even in troubled times.

According to the paperwork filed Friday, Sports Authority’s contract with the Broncos includes the following terms:

• From 2011 to 2020, Sports Authority will make graduated payments ranging from $3.77 million to $5.27 million. Those payments are due quarterly.

• The naming-rights portion of the contract expires in 2020. At that point, the sponsorship portion of the agreement will continue with payments of $1 million per year (reduced to $500,000 for 2021 to 2024 as reimbursement for the costs of the stadium logo change).

• Sports Authority is the Broncos’ exclusive sponsor in the retail sporting goods category

• Sports Authority will have presenting sponsorship of and the banner ad on every page of the “Tickets and Stadium” section at DenverBroncos.com; ticket-back advertising; and two 30-second TV spots

• Three player appearances per season at mutually agreed upon events

Additionally, Sports Authority’s hospitality benefits from the agreement include:

• Rent-free use of the stadium for two large events (of up to 900 people) and 20 small events (of no more than 20 people) per year

• Access to 16 pre-game field passes for every home game

• Opportunity for four guests to travel on the Broncos team plane to every regular season away game

• Use of Suite 216, 32-seat box suite next to owner’s box, for home games

• Four Super Bowl tickets

• Right to purchase 500 tickets in best available locations at face value for non-Broncos events

Alicia Wallace: 303-954-1939, awallace@denverpost.com or @aliciawallace