ENGLEWOOD, Colo. — The Super Bowl champs begin training camp Thursday with major questions on both sides of the ball, beginning with who will be the one throwing it.

General manager John Elway declared the Denver Broncos' quarterback competition wide open.

Coach Gary Kubiak said he'll split snaps between Mark Sanchez, Trevor Siemian and Paxton Lynch, beginning — but not set — in that order.

"Gary is very seasoned at that position, so I know he's going to handle it the right way and we'll find the right guy," Elway said.

There are also unknowns on defense such as when star cornerback Aqib Talib and pass-rusher DeMarcus Ware will be cleared to practice. Both are starting out on the non-football injury list, Ware after aggravating a bad back in the offseason and Talib after suffering a gunshot wound to his right leg.

While acknowledging it's hard to top a Super Bowl triumph, Elway said he expects his offense to be better this year no matter who wins the quarterback job. He insisted his standards don't dip just because he doesn't have an elite passer for the first time in four years.

"Our job is to be competitive and try to win a championship year in and year out," Elway said.

Kubiak has said "we should know a lot more in about a week" about who has the inside track to the job, but he declined to say how deep into camp he's willing to hold open the audition.

The winner gets to direct an offense that Elway reconstructed this offseason following Denver's 24-10 win over Carolina in Super Bowl 50 and the departures of Peyton Manning to retirement and Brock Osweiler to free agency.

The Broncos have just four offensive starters from the Super Bowl returning to their same position: center Matt Paradis, running back C.J. Anderson and wide receivers Emmanuel Sanders and Demaryius Thomas.

"I think we can be better offensively," Elway said, citing the return to health of some players and better familiarity in Year 2 under Kubiak, who no longer has to operate a hybrid offense to accommodate Manning.

"As much as we like to say that we did the right things offensively (last season), we HUNG ON offensively," Elway said.

Led by linebackers Von Miller and Brandon Marshall, both of whom signed big contracts this summer, the defense returns all but two starters. Elway said he trusts the Broncos have the depth to seamlessly replace Malik Jackson and Danny Trevathan, who followed Osweiler out of Denver in free agency.

Kubiak said Talib should be back in action "real soon." But even if he is, possible NFL punishment and legal ramifications hang over the star cornerback who was shot in his right leg in Dallas on June 5. Police are investigating whether Talib accidentally shot himself.

"When I heard the news, I was just thankful that he was OK," Elway said.

The GM met face-to-face with Miller on Wednesday for the first time since protracted contract negotiations that grew contentious before Miller signed a deal that guarantees him $70 million, a record for a nonquarterback.

Elway said he wanted to make sure there were no hard feelings, and Miller said there weren't any.

Elway said he also told Miller that standards soar commensurate with his weightier wallet.

"I'm aware of the expectations," Miller said. "But we have high expectations on all of us."

The sides signed off on the $114.5 million, six-year contract about two hours before the July 15 deadline.

"I was expecting it to be a day or like a couple of hours," Miller said before dodging a question about reports he and his agent sought permission to seek a trade at one point.

"Ultimately, I wanted to be a Denver Bronco for life and I feel like we got that done," Miller said. "The business is the business, but ultimately I wanted to be a Denver Bronco at the end of the day."