2018 Case Keenum looks a lot like 2013-16 Case Keenum instead of 2017 Case Keenum, but the Broncos are still sticking with their starting quarterback. 

After the Broncos dropped their fourth straight game, this one a 23-20 loss to the Rams that wasn't as close as the final scoreline suggested, Broncos coach Vance Joseph told reporters that he doesn't plan to make a quarterback change.

Entering Sunday's game, Keenum had completed 63.5 percent of his passes, averaged 7.1 yards per attempt, thrown two more interceptions (7) than touchdowns (5), and posted a 78.1 passer rating. He's looked nothing like the quarterback he was for the Vikings a year ago, when he led them to the NFC Championship Game and emerged as a fringy MVP candidate. But his return to inadequacy is not at all surprising considering this is a quarterback who posted backup numbers year after year until he arrived in Minnesota.

Keenum actually played better on Sunday, going 25 of 41 for 322 yards, two touchdowns, one pick, and a 91.7 passer rating, but his subpar first half contributed to the Broncos' 10-point deficit at halftime -- not to mention his final, stat-boosting touchdown pass came with 1:22 remaining in a game that was pretty much over. 

The pressure is mounting for Keenum to improve. Otherwise, he might just be replaced. 

If Broncos fans ran their team, they might've already made the switch. For one, there were the boos that rained down.

And then there were the cheers for Kelly. It came as no surprise to hear the fans in Denver react favorably when backup quarterback Chad Kelly, who beat out former first-round pick Paxton Lynch for the backup job this summer despite nearly going undrafted in 2017, briefly entered the game at the end of the first half to take a knee with Keenum getting checked out for a concussion.

And Broncos fans went crazy. As The Athletic's Lindsay Jones put it on Twitter, "the home crowd cheers the s--- out of Chad Kelly taking a knee."

But when the second half began, it was Keenum back under center again. And after the game, Joseph supported his starting quarterback. 

The backup quarterback is almost always the most popular player on a team with a bad starting quarterback, which doesn't always make promoting the backup the right move. But in this case, the Broncos don't have much to lose by inserting Kelly into the starting lineup. Keenum isn't their quarterback of the future. It's beyond clear that he's nothing more than a bridge quarterback. The Broncos cut Lynch before the season. The bridge leads to Kelly right now.

Unlike Keenum, Kelly isn't a known commodity. He's a 24-year-old former seventh-round pick who's never thrown a pass in a real NFL game. The Broncos are 2-4. They're not in contention. They should probably find out what they have in Kelly before next year's draft so they can plan accordingly. 

The Broncos are on a short week, playing the Cardinals on Thursday night. Then they get 10 days before playing the Chiefs. That could be when the Broncos decide to make a change if Keenum struggles again. If not then, they could promote Kelly during their Week 10 bye. 

At this point, despite what Joseph said Sunday, it seems like more of a question of when and less of a question of if.