ENGLEWOOD, Colo. — Gary Kubiak always had a definitive answer last season when he gathered his players every Monday to let them know whether Peyton Manning or Brock Osweiler would start that week.

He tried to exude the same certainty a day after Trevor Siemian suffered a sprained left shoulder and rookie Paxton Lynch closed out Denver’s 27-7 rout of Tampa Bay with an impressive NFL debut.

“Trevor is our starting quarterback,” Kubiak said, “and hopefully he is going to be OK. I’m really proud of Paxton and how he came in and played yesterday.”

A week after becoming the first player in league history with 300 passing yards, four TD passes and zero interceptions in his first career road start, Siemian was off to another solid start Sunday. But he was sacked by Bucs defensive tackle Clinton McDonald, who slung the Broncos quarterback to the turf on his left shoulder for an 8-yard loss late in the second quarter.

Siemian left the field on his own following his third sack and later received a ride to the locker room on a cart. He donned a baseball cap after halftime, finishing 5 for 7 for 68 yards, including an 11-yard TD pass to Demaryius Thomas on Denver’s first offensive play.

Lynch completed 14 of 24 passes for 170 yards and a TD to Emmanuel Sanders and engineered a 16-play scoring drive coming out of the break that chewed up more than half of the third quarter.

Impressive as Lynch was in relief, Siemian, the 250th overall draft pick in 2015, has now outdueled three overall No. 1 picks in his first month as a starter: Cam Newton, Andrew Luck and Jameis Winston.

Kubiak said Siemian was day to day with a sprained left shoulder, and the quarterback appeared to be in his usual high spirts as he zipped through the locker room Monday without stopping to take questions.

“Obviously, it’s his non-throwing shoulder, so it’s about getting him to where he feels like he can go through the motion again,” Kubiak said, noting it would be a matter both of pain tolerance and mechanics. “Throwing the ball is not going to be a problem, it’s how does it feel when he moves his whole trunk. We’ll have to see.”

Kubiak said he won’t make a definitive decision on his starter until week’s end but noted the cerebral Siemian could miss much of the week’s practice and still get the starting nod Sunday.

If Siemian is a no-go, however, Lynch, the 26th overall pick out of Memphis in the NFL draft this spring, would make his first start when the Broncos (4-0) host the Atlanta Falcons (3-1) in the biggest showdown of the young NFL season.

Kubiak deftly handled his quarterback quandary with two veterans last season as he guided the Broncos to the Super Bowl title and now he faces a similar task with a pair of novices.

While Kubiak’s three-way QB competition between Siemian, Lynch and veteran Mark Sanchez during training camp raised lots of eyebrows, the setup is paying off.

“We saw it work yesterday with Paxton,” wide receiver Bennie Fowler said. “He comes in, we don’t miss a beat.”

After losing Manning to retirement and Osweiler to free agency, Kubiak had no qualms about going with Siemian and Lynch even though neither had ever thrown a pass in an NFL game. So, the Broncos released Sanchez and signed journeyman Austin Davis as the third QB.

Kubiak sees his pair of young QBs not as a liability but as an embarrassment of riches.

“We’re probably going to need them both. It’s just kind of the nature of the business nowadays,” Kubiak said. “Here we are, four weeks into the season, and we’ve used them both to get to where we’re at. It’s exciting to watch both of them grow and both of them prepare each week. I think they both have bright futures. That’s great for our organization.”

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