ENGLEWOOD, Colo. --As expected, Trevor Siemian and Paxton Lynch are listed as co-No. 1 quarterbacks on the first depth chart of the preseason, which was issued by the Broncos on Monday morning before they returned to practice after their Sunday off-day.Siemian and Lynch have split first-team repetitions, alternating periods with the No. 1 offense since the start of organized team activities in May. This arrangement is expected to continue until one of the quarterbacks has made enough separation to lead to a decision as to who will start in Week 1.

During Saturday's scrimmage, Siemian and Lynch took turns with the first and second units. Siemian led the No. 1 offense to a first down and went three-and-out with the second team. Lynch threw an interception with the No. 1 offense, then completed a pass for a first down with the second team, only to have the yardage wiped out on a post-play penalty by OT Donald Stephenson.

This marks the second consecutive year that the Broncos have had co-No. 1 quarterbacks heading into the preseason opener.

Quarterback is the only position at which co-starters were listed.

Other notes on the depth chart: First-round pick Garett Bolles is the first-team left tackle, listed ahead of third-year veteran Ty Sambrailo. Bolles has split first-team repetitions with Sambrailo and Donald Stephenson since minicamp. Head Coach Vance Joseph said throughout the offseason that while Bolles was a first-round pick for a reason, he wanted him to earn the job; he appears to have done that.

Bolles is one of two rookies on the first team; he is joined by WR Isaiah McKenzie. Joseph announced Saturday that McKenzie had earned the punt returner job; he is listed ahead of second-year veteran Kalif Raymond. McKenzie is also listed as a third-team receiver.

DeMarcus Walker is listed as the second-team weak-side outside linebacker behind Von Miller. Walker was drafted as a defensive end, but was moved to outside linebacker in the wake of injuries to Shane Ray and Shaquil Barrett, who are still the first- and second-team strong-side linebackers but are indicated in brackets because of injuries that are expected to sideline them until the regular season.

Walker is one of two rookies on the second team; he is joined by CB Brendan Langley, who is listed ahead of third-year veteran Lorenzo Doss, and WR Carlos Henderson, who is the No. 2 kickoff returner behind fourth-year veteran Cody Latimer.

Seventh-year veteran Virgil Green is atop the depth chart at tight end, followed by Jeff Heuerman, A.J. Derby, Austin Traylor and Steven Scheu. Green is one of just two players who had prior experience playing with the Broncos under current Offensive Coordinator Mike McCoy (Demaryius Thomas is the other).

Latimer and Bennie Fowler III are the second-team wide receivers behind Thomas and Emmanuel Sanders. McKenzie and Jordan Taylor are the third-teamers, followed by Henderson and Raymond. Anthony Nash and Marlon Brown are the fifth-team wide receivers, with Hunter Sharp rounding out the depth chart.

C.J. Anderson leads off the running-back corps. Injured Devontae Booker is the No. 2 running back, followed by Jamaal Charles, Stevan Ridley, De'Angelo Henderson, Juwan Thompson and Bernard Pierce.