ENGLEWOOD, Colo. -- Right now it feels as if anything said about the Denver Broncos' wide receivers should end with a question mark.

Start with the fact that even their most experienced, most proven, most reliable wideout -- Emmanuel Sanders -- is coming back from a torn Achilles tendon he suffered in December.

Sanders has continued to make steady progress in his return and consistently says he is on track to be fully involved in the offense by the time the Sept. 9 regular-season opener at the Oakland Raiders rolls around. But he still is not a full participant in practice.

He is the only wide receiver on the roster who has had a 45-catch season. Courtland Sutton caught 42 passes as a rookie in 2018, and no one else has topped 30 catches in a professional season.

The state of affairs among the pass-catchers is wide open as the team approaches Thursday's second preseason game.

Things are so unsettled that Nick Williams, who didn't arrive until after training camp had opened, has a chance to carve out a roster spot if he continues to flash as a slot receiver in the offense and finds a role on special teams.

Uncertainty abounds. The team saw a pile of dropped passes early in training camp, a sideline fight during Monday's practice between Sanders and Sutton and injuries to DaeSean Hamilton and River Cracraft. Sprinkle in a crowd of young quarterbacks after Joe Flacco on the depth chart, including rookies Drew Lock and Brett Rypien, and the passing game has simply looked clunky at times as offensive coordinator Rich Scangarello continues to install the new scheme.

"In the end, our job is to be at our best come September when we start the season," Scangarello said recently. " ... I know when you're watching it, things are going to look a certain way offensively and defensively. And rightfully so to say the offense struggled, or whatever. I understand all that from the outside.

"For us, it's about measuring -- we are putting in different schemes and things don't necessarily fit what we're seeing and what we have to teach the quarterback and the players -- and you have to install things. So, it's not always going to be smooth. ... I think offensively we've just got to jell, [and] we're coming together. By far, we're not there, we still have ways to go, but I feel the confidence. I think Joe has settled in a little bit. ... I think there is some confidence growing, but we are a long way away."

Youth is a factor, as well. After Sanders, who is entering his 10th season, and Williams, who is in his sixth season but just arrived in July, the Broncos don't have a another wide receiver who has appeared in more than 16 games.

Scangarello certainly intends to involve the running backs and tight ends more in the passing game, including lining up the likes of Phillip Lindsay and Noah Fant out wide at times. But at its best, Scangarello's scheme -- which has roots in Mike Shanahan's and Gary Kubiak's versions -- needs wideouts who can go beyond the drumbeat of short and intermediate routes to turn the play-action into big plays down the field.

Hamilton, whose meticulous route running has made him a popular option for Flacco in practices thus far, might have spoken for the group when he was asked what it would take to consistently get the ball.

"Really, just be somebody that obviously Joe can rely on, somebody that obviously Joe can really just look anywhere on the field and hopefully have some separation," Hamilton said. "A guy he can just put the ball on and be able to make a play for him. That's really just what I try to come out and do every day. Somebody that is consistent, gets consistent separation, be able to make plays and somebody that he can rely on to pick up the first down, obviously make the catch."