ENGLEWOOD, Colo. -- The Denver Broncos roll into Week 9 against the Cleveland Browns with two quarterbacks whose combined NFL starts add up to zero.

In fact, quarterbacks Brandon Allen, Brett Rypien and Drew Lock have played a combined zero regular-season snaps. But this is where the Broncos are with Allen set to start in place of the injured Joe Flacco against the Browns on Sunday (4:25 p.m. ET, CBS). Rookie Rypien is expected to be the backup.

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“I don’t know if surprised is the right word -- I’ve obviously worked for it,’’ Allen said. “It has taken it a while. You never want to see a starter go down and so we’re feeling for Joe right now, but this is the opportunity you work for.’’

An opportunity three-plus seasons, three trips through the waiver wire and two waiver claims in the making. Allen was a sixth-round pick by the Jacksonville Jaguars -- the 201st player selected overall -- in the 2016 draft. Since, Allen has been on the Jaguars' and Los Angeles Rams' rosters, had a short stint on Rams injured reserve, been on the Rams' practice squad and been Flacco’s backup since the Broncos claimed him off waivers Sept. 1.

It's been 42 months since he heard his name called in the 2016 draft; now Allen, 27, had his chance.

“I don’t think I questioned it, it’s just something I’ve always worked for and tried to be ready for,’’ Allen said. “It’s just something you work for. ... It’s a great opportunity.’’

Flacco is expected to miss five to six weeks with a herniated disk in his neck. The 34-year-old said after Sunday’s loss at Indianapolis he had felt discomfort and pain in his neck “for a couple weeks," and he wasn’t certain if a single play made the pain significantly worse in the second half against the Colts.

Flacco received a second opinion on the injury Tuesday after the Broncos’ medical staff evaluated him Monday, including an MRI. The belief is that Flacco will not need surgery, but coach Vic Fangio said Monday “we’re still gathering information." Flacco will be evaluated again after the Broncos’ Week 10 bye next week.

In the meantime, Allen will be the sixth different starter for the Broncos (2-6) since the start of the 2017 season.

Allen does bring two years’ worth of experience in the Rams' offense to the job. It's a similar scheme, in terms of the play-action, rollout work in the passing game and work under center and the shotgun. As Flacco’s backup since the start of the regular season, he has received a smattering of plays with the starting offense.

“[I’m] very comfortable, it’s a very a similar offense from where I came from, even when I first got here I was fairly comfortable,’’ Allen said. “Here and there every week there’s a couple plays they give me just to be able to get in with the first O.’’

Rypien has been on Denver's practice squad after the team released him when rosters were trimmed Aug. 31 to 53 players, so his on-field work has largely been limited to running the scout team each week. Rypien had been signed as an undrafted rookie and spent the offseason and training camp with the Broncos. And with given the presence of Lock, a second-round pick this past April, Rypien said Tuesday he’s not going to focus on much beyond the present.

“I don’t really worry about things I can’t control," Rypien said. “And obviously that’s something I can’t control, what my place is on this team."

Lock hasn’t participated in practice since mid-August -- he suffered a right thumb injury in the Broncos’ preseason game against the San Francisco 49ers -- and is on injured reserve. Lock said he has considered himself healthy enough to throw “for about two weeks.’’ But because Lock has missed so much time, Fangio said the Broncos don't have a timetable for his return to practice, let alone the roster.

“Obviously I trust them to put the plan in place whenever they feel it’s necessary," Lock said, "whenever they feel it’s best for me to come back and practice or come back and play ... because, like I said, I haven’t taken a snap with anyone, so when I come back they want to get me some practice reps before they put me into a game.’’

All of that means it’s Allen behind center for a team whose complex is filled with photos of John Elway and Peyton Manning. Allen has been counselor at the Manning Passing Academy, so he knows the deal.

“It’s exciting, I’m very excited,’’ Allen said. “Obviously this is the opportunity everybody wants, everybody strives for, I’m going out to do the best I can do. ... Not saying [Allen's relatives] weren’t watching before, but they’ll be here.’’