ENGLEWOOD, Colo. — This past offseason was the first in which Denver Broncos general manager John Elway had to make hard choices because of the salary cap. And after a season in which his defense endured long stretches of struggle, he had to sacrifice offensive contributors — and gamble on internal or less-expensive imports to replace them.

The most prominent offensive starter to leave was wide receiver Eric Decker, who signed a five-year deal that could be worth up to $36.5 million.

“I knew I wasn’t going to get signed back before that time,” said Decker. “I kind of knew what direction they wanted to go in.”

“The business part of the NFL is the worst side of it. You’d like to keep every single player or play with every single teammate your entire career,” added quarterback Peyton Manning. “But it’s not like college: there’s a small window and guys move on, so I was happy with him and how he was rewarded by the Jets.”

The Broncos have moved on, as well, and Emmanuel Sanders has been a credible replacement for Decker. Although the ex-Pittsburgh Steeler has yet to score a touchdown, he’s posted the first 100-yard games of his career — three in succession — and is on a 128-reception, 1,740-yard pace through four games. The offense is fine without Decker, and Manning is on pace for 48 touchdown passes.

But he feels fondness for Decker, who, along with Demaryius Thomas, smoothed Manning’s transition and provided him two outside weapons that allowed the Denver offense to rejoin the league’s elite soon after Manning’s arrival.

“He’s one of the first guys that I threw to when I signed here in the spring of 2012,” said Manning. “We developed a pretty good rapport early. Eric kept himself in great shape. He was healthy, not just for games but for practice, which I’ve always said the only way to develop any type of timing and chemistry is when you’re out there every day. Great work ethic, really took care of himself. I was sorry to see him go.”

Decker has been unable to match the pace he set the last two years with the Broncos. That happens when you exchange Manning for Geno Smith, whose struggles led Jets coach Rex Ryan to bench him last week.

Smith will start this Sunday, and the Jets hope Decker will, too; he was limited Wednesday because of a hamstring injury. If he plays, he’ll be a familiar foe to many Broncos — but only one of their top three cornerbacks: Chris Harris. Starter Aqib Talib and nickel back Bradley Roby were not with the team last year.

Harris knows he will have to offer a tweak or two, since Decker knows him well from daily repetitions in practice for the previous three seasons after Harris arrived as an undrafted free agent.

“I’m all reaction, so I’ve got to react off what Deck’s doing. He knows how I play. He knows I’m going to be physical, so I’m going to switch it up on him,” Harris said. “I’m not going to give him anything that he’s seen a lot from when he’s practicing.”

Of course, how much Decker gives will be determined by what his quarterback — or quarterbacks — can give him.

“I know going against Decker is going to be a tough battle,” Harris said. “Especially because I know he’s going to come out even more amped against us. And they might try to feed him the ball a little bit more.”

And it will then be up to Harris and the defense to ensure that Decker does not take out any frustrations on the team that decided to spend its money elsewhere.