Mike & Mike are baffled by Chuck Pagano's failure to lead the Colts to victory during their game against the Lions. (2:00)

Greeny: Pagano did everything he could to give game away (2:00)

INDIANAPOLIS -- Denver Broncos starting quarterback Trevor Siemian's NFL resume consists of two games and just one start.

That means the Indianapolis Colts are catching a break because they'll be facing an inexperienced quarterback in Denver on Sunday, right?

Wrong for a couple of reasons.

Siemian won his first start against the Carolina Panthers in Week 1. But more importantly, the Colts have zero -- a gigantic zero -- reason to look past any opponent after their performance against the Detroit Lions on Sunday.

"If the offense scores that many points, we should be able to close the deal, especially with 35-36 seconds left on the clock," Mike Adams said of Sunday's loss. "Regardless of what happened before that, we had a chance to close the deal." Zach Bolinger/Icon Sportswire

The defense spoiled an impressive performance by the offense when they gave up 37 points and 448 total yards in their 39-35 loss.

There's no excuse for the Colts losing that game when Andrew Luck & Co. scored 35 points.

"That should be enough," safety Mike Adams said. "No question. And that's what's frustrating to me. If the offense scores that many points, we should be able to close the deal, especially with 35-36 seconds left on the clock. Regardless of what happened before that, we had a chance to close the deal."

It shouldn't be surprising that the defense let the offense down. That's been the case on a regular basis since Luck and coach Chuck Pagano arrived in 2012. The Colts have finished in the top 20 in total defense just once in Pagano's first four seasons.

Sunday was the 18th time that the Colts had given up at least 30 points since 2012. They're 3-15 in those games.

It didn't help that the Colts went into the game without cornerback Vontae Davis (ankle), cornerback Darius Butler (ankle), defensive lineman Henry Anderson (knee) and safety Clayton Geathers (foot). Then they lost cornerback Patrick Robinson (concussion) and safety T.J. Green

Adams has no interest using the high number of injuries as a crutch for the defensive problems.

"You are wasting time making excuses because this is the NFL," he said. "The guys that came in they are getting paid. They are getting paid to do a job and obviously they are capable. They are here because they are capable. So we expect them to step up when it's time. That's how I got my shot when I was a young pup. Someone got hurt and I stepped in. No one made excuses for me saying, 'It's OK he's a rookie,' or 'He didn't know that's why he didn't make that tackle.' We're not going to do that. We're not going to play that game."

The Colts will have to continue to make do with what they have at the moment, but with some of their injured players close to returning, Indianapolis will have a better indication of how they'll be defensively.

The Colts are hoping to give Butler and Geathers some practice time Wednesday. Anderson's practice workload will continue to slowly be increased.

That'll be the start to what's been a long road to recovery for a defensive unit that has been lacking an identity since Day 1 of training camp in late July.

"We always talk about how this is an offensive team," Adams said. "As a defense we were saying, 'Let's take that out of their hands. Let us be a defensive team.' We failed. There's no panic, believe it."