Anger still boiled within Melvin Gordon the day after what he considers rock bottom of his football career. It bubbled in him like a stew, smoldering in embarrassment and frustration, forming the type of medley that, if not digested, can consume an NFL rookie.

This is how wide receiver Dontrelle Inman found him, sitting on a black leather couch inside the Chargers’ locker room. He saw Gordon needed help, something to fan the flames.

Inman had the key.

“It’s called a Giving Key,” Inman said.

Inman had a gold necklace with a bulky, engraved household key on it — “had” because he gave it to Gordon. Gordon had the necklace and wore it every day — “had” because he gave it to another teammate. The relic has been passed around, a symbol to a still tight-knit team that on Sunday will host the rival Broncos.

The Chargers hoped, from a playoff standpoint, more would be on the line.

This is the first of four AFC West games in the final five weeks. They hoped this would be where they’d solidify a postseason run. They are 3-8. They won’t. Important to them is ending the season in proper fashion.

That means staying together.

That means strength.

“Strength” is the word engraved into the Giving Key that Inman gave Gordon. He bought two such necklaces at Kinson, a store located on San Diego’s harbor in Seaport Village, and is still looking for someone to whom he’ll give the other. The second key has “inspire” as its engraving.

“You can purchase a key or somebody gives it to you,” Inman said. “But if you find someone who needs it more than you do, you give it to them.”

Like his team, Gordon, a first-round draft pick, has dealt with adversity this year.

The pinnacle came Oct. 18 when the Kenosha native returned to Wisconsin for a game against the Packers. Family and friends were there in Green Bay, a couple-hour drive from where he went to college in Madison. Gordon was an honorary team captain.

The game began. He fumbled in the first quarter. He exited with an injury, walking to the locker room for what the team announced as a foot ailment. He returned in the second quarter only to fumble a second time. He was benched for the game’s remainder.

“I was in a bad place,” Gordon said. “That was probably an all-time low for me. … I don’t know how anyone else felt about it, but it was a tough time for me at the moment, just a point in time where I had to be strong, really. ... You always look at your chest. You see the key around you. You see it on there. It says it. It’s just a reminder to keep strength, keep faith.”

“I knew it was an important time in his career, an important time in his season,” Inman said. “I didn’t want him to lose strength. I didn’t want him to lose confidence in himself.”

Be it coach Mike McCoy, offensive coordinator Frank Reich or quarterback Philip Rivers, many cited the exchange as a testament to the larger culture at Chargers Park. Reich called it “the kind of stuff that gives you goosebumps.”

Inman learned about Giving Keys from safety Darrell Stuckey and running back Danny Woodhead. Stuckey bought two before the season. One, engraved with “fearless,” he kept for himself. The other, “create,” he gave to Woodhead, he said, because Woodhead has a knack for creating a positive atmosphere.

Gordon wore his necklace for weeks.

Then, he found someone who, he felt, needed it more.

Wide receiver Keenan Allen caught 67 passes in the season’s first eight games, tied for third-most in NFL history. The 67th was his last, as Allen plucked a touchdown on Nov. 1 in Baltimore but landed hard on the ground. He was hospitalized that night in San Diego with a lacerated kidney, which ended his season.

Coaches and teammates were among those to visit Allen in the hospital, offering their support.

After he was released, Gordon gave him Strength.

“He just laughed,” Gordon said. “‘What am I supposed to do with this?’ I said, ‘Hey, bro. It’s just what we do.’”