ENGLEWOOD, Colo. — Vance Joseph’s had Case Keenum’s back through it all this year.

On Monday, however, following the worst offensive performance to date, Joseph’s tone changed when talking about his signal caller, specifically offering one tweak he wants to see in his game.

“He’s got to make plays,” Joseph said bluntly after touching on the subject multiple times earlier in his Monday press conference.

While Denver’s offense has done enough over the past month to go 3-1, they’ve only averaged 21.25 points per game. Of that output, their passing game has only accounted for an average of seven points per game during that span.

“I thought Case has played his best football the last month,” Joseph said, buttering him up before diving in. “Yesterday, he was a little cautious with the ball. Bottom line, we’ve got three weeks to play. He’s got to make more plays. Sometimes, taking some chances allows you to make more plays. There’s going to be turnovers, so he can’t worry about that.”

After starting the season with 10 interceptions over his first eight games, Keenum’s been clean with the football, throwing zero interceptions over his last five.

However, just as the interceptions have vanished, so have the big plays.

In his five clean games, Keenum’s longest pass plays have been for 21, 30, 38, 39 and 44 yards, while his passer rating is just 3.7 points higher than his first eight games of the season.

After dropping just 14 points on the lowly 3-10 San Francisco 49ers on Sunday, Joseph needs to see a philosophical change from his quarterback.

“You can’t play this game perfect,” Joseph said, explaining that turnovers are okay. “But I want Case to be more aggressive, especially down the seams of those Cover-3 defenses — that’s where the soft spots are. He’s got to be aggressive down the seams and not worry about making mistakes.”

In the high-flying, new-age NFL, Keenum has averaged just over 205 passing yards per game in his last five games in which he’s been interception-free.

So the question is why? Why has Keenum completely avoided taking the big shot? Why has the $18-million quarterback shied away from taking chances?

“I think it’s a combination of Case wants to be safe with the ball and obviously seeing different looks,” Joseph said. “In my opinion, being safe with the ball sometimes it allows you to have great numbers in that category, but as far as making plays down the field, you can’t be safe doing that. He’s got to take more chances down the middle of the field. He would tell you that.”

On Sunday, Case did exactly what his head coach wanted him to do on the very first play of the game — took a shot deep down the field to Courtland Sutton.

After the incompletion, however, there were no more deep shots to be found.

“We had some chances down the field. We didn’t hit them. We missed three or four chances to make some big plays in the pass game,” Joseph said, all but shouldering the blame directly on No. 4.

“This defense that we played, they were in single-high all day — Cover 3 or Cover 4 all day. We knew going into the game running the football was going to be tough because of the loaded boxes, so you have to make plays with our pass game versus those types of defenses to kind of soften them up a bit. And we didn’t make those plays. And they were there. And we didn’t make them.”

With three games left, and any hope of a shot at the playoffs on the line each and every week, Keenum can’t play scared.

On Monday, his coach went against conventional thinking and all but begged him to take chances.