ALAMEDA, Calif. -- In a season of ugliness, the Denver Broncos turned the clock back to 1967 on Sunday against the Oakland Raiders.

With a 21-14 loss to one of their former AFL brethren at Oakland-Alameda Coliseum, the Broncos constructed their first seven-game losing streak since the pre-merger NFL. The Broncos lost nine in a row that season, a little slice of history that appears poised to repeat itself, as the Broncos can't stop the current cave-in even as the formerly benched Trevor Siemian might be asked to keep it from happening.

In Sunday's loss alone, defensive end Derek Wolfe left the game with a neck injury, cornerback Aqib Talib -- a team captain -- was one of the players ejected after the two teams' first-quarter brawl, and Paxton Lynch’s first start of the season was an expectedly choppy affair that ended when Lynch left the game with a right ankle injury in the third quarter.

What happened to Lynch was not a mystery. The Broncos have struggled to protect any and all of their quarterbacks the entire season, especially when they’re behind and forced to play out of a three-wide-receiver set.

They trailed 7-0 midway through the second quarter, 14-0 late in the first half and 21-0 with 6:22 left in the third quarter. That is not the ideal situation for any quarterback, especially not one such as Lynch, who got a new offensive coordinator on Monday, battled confidence issues in training camp and missed September as well as October practices with a shoulder injury.

Lynch was 5-of-10 passing for 22 yards at halftime -- 19 of those yards came on one pass -- and 9-of-14 for 41 yards when he left the game. He had a quirky deflection that turned into an interception, and he was sacked four times. In short, all of that missed practice time is going to show up in a player who watched the Broncos’ offensive woes chew up and spit out Siemian and Brock Osweiler.

The immediate future, however, might be in Siemian's hands again, as Lynch left the game with 4:55 left in the third quarter. He had been limping after several plays before he finally stayed down, near the Broncos’ sideline, after a 1-yard completion to Emmanuel Sanders.

It all makes the Broncos' quarterback position -- in which all three players have started and all three players have been a game-day inactive for at least one game this season -- even messier.

The Broncos have had scouts at many college games to watch marquee QBs such as Sam Darnold, Josh Rosen, Josh Allen and Baker Mayfield. Depending on who is on the board by the time April rolls around, the Broncos will have the information they need to make a decision.

Given that they are in the process of playing themselves into one of the prime spots in the draft order, the kind of spot they haven’t had since they took Von Miller with the No. 2 pick in 2011, the Broncos might have their best opportunity to take a quarterback at the top of the board since '11. They traded up to get Lynch in the first round of the 2016 draft, and Lynch’s transition from Memphis’ spread offense to what the NFL demands from the pocket has been difficult.

It won’t get any easier if Lynch's ankle allows him to get back behind center down the stretch in a lost season. Siemian, for his part, has made it clear that despite being benched earlier this season and being a game-day inactive last week against the Cincinnati Bengals, he's the Broncos' best option at quarterback. He delivered two fourth-quarter touchdown drives on Sunday.

In the end, those touchdown drives, or the fact that the Broncos' defense couldn't get a third-down stop in the final minutes to give them a last hope, or the fact that the Broncos lost by a touchdown to a team without its top two receivers and a team that fired its defensive coordinator this week didn’t matter much.

The Broncos have a to-do list that keeps growing every week.

Quarterback will be at the top of it.