ENGLEWOOD, Colo. -- As August grinds toward the NFL's regular season, the annual debate about how many preseason games is enough has bubbled up again.

"It seems like we're always talking about the preseason," Denver Broncos cornerback Chris Harris Jr. said. "Guys who know how to prepare are ready for the regular season pretty fast."

The Broncos are holding joint practices at their suburban Denver complex with the San Francisco 49ers on Friday and Saturday, a common occurrence in training camps across the league. And as the league and the NFL Players Association attempt to negotiate a new labor deal, there are people around the league who believe joint practices could offer a substitute for some, or all, preseason games in the future.

Niners coach Kyle Shanahan went as far as to say he could glean more information on his players from a joint practice than from a preseason game.

"You absolutely don't need four preseason games," Shanahan said earlier in training camp. "I'd rather have zero than four, preferably I'd like two. One to evaluate the people trying to make the team and then just one to knock a little rust off."

Then asked if he would put a lot more value on a joint practice session than he would a preseason game, Shanahan said simply: "A ton more value, yeah."

Joint practices are certainly nothing new. Pittsburgh Steelers coach Bill Cowher eagerly extolled the virtues of such workouts during his rookie season as a head coach in 1992, and Jeff Fisher said he hoped "to get a lot of good work, almost like a game," before the Houston Oilers and Dallas Cowboys held a joint practice in 1996.

Sean McVay of the Los Angeles Rams comes from the same school of thought as Shanahan -- the two coached together under Mike Shanahan with the Washington Redskins, after all -- and sees greater value in joint practices than games. Since McVay took over as coach in 2017, the Rams have had regular joint practices during training camp. He uses mostly starters and key backups, not reserves and end-of-the-roster guys. On the flip side, he does not use starters in the preseason, but uses those games to evaluate young or inexperienced players.

"Definitely a little bit more competitive," Rams quarterback Jared Goff said of a recent practice with the Chargers. "... I prefer them over preseason games, honestly, because we're able to get the work in a controlled environment.

Goff said that the offensive line had 40 or 50 reps against Chargers defensive ends Joey Bosa and Melvin Ingram and the defensive line. Whereas, in a preseason game, the defensive line might get five or 10, he said.

For other coaches, it's a chance to do something different.

"It gives you more reps and also gives you different kinds of reps," Cowboys coach Jason Garrett said. "Maybe you're going against a different scheme, you've seen some plays or defenses that you haven't seen before. Some stuff in the kicking game that isn't what you do. So those are all really positive experiences.

"I do think the teams have to be like-minded in what they want to get to of it. You don't want to make it into a fighting session. That's not really the objective of it. You certainly want to make it competitive. You want to go to that line, but you don't want to cross that line."

Fighting is a concern. Things got so bad between the Cowboys and Rams in 2015 that the coaches called off the last 20 minutes because all the teams did was fight. The Cowboys haven't held a joint practice since. For coaches like Ron Rivera of the Carolina Panthers, there's a no-tolerance policy on fighting.

"If anybody fights then we'll pull them out and throw them out of practice and they'll have to be disciplined," Rivera said. "We're not here to fight. That's bulls---."

Teams such as the New York Jets, Seattle Seahawks and Kansas City Chiefs have opted against joint practices. While Andy Reid, who has not held a joint practice since coming to Kansas City, has had bad experiences with fighting, it's more about keeping the team's secrets safe.

"We try to teach on the field," Reid said. "... We try to teach as we're doing it. I really don't want anybody hearing that. That's my own personal feeling. As much as I can keep in house in today's world I'd like to. You give up a little bit of that when you work [with another team]."

Most of the hand-wringing about playing preseason games can be traced to the threat of injury. Coaches are not nearly as concerned about injuries in joint practices because there's no tackling, and all players are told to stay off the ground, versus in a preseason game, when there is tackling and no coaches standing on the field.

Developmentally there is a feeling that two sessions of joint practices, perhaps one or two weeks apart, would allow teams to make decisions on their younger players as well as new arrivals as rosters go from 90 to 53. There is even a better chance those decisions could be made if regular-season rosters were expanded in any new collective bargaining agreement.

"To me -- I must have done more than 40 of these over the years and -- it's just great to go against somebody else," Broncos coach Vic Fangio said. "Offensive linemen having to block different pass-rushers and run block different D-linemen, corners covering different receivers, wide receivers going against different corners, different schemes. I think it's great. I would do two of them a camp if I could."

Beyond the football, any change in the structure of the preseason probably would come down to what many of the league's issues do -- money. Unlike the regular season, teams do not have to share certain revenues in the preseason that they share in the regular season.

And given that teams charge regular-season ticket prices in the preseason as well, and include the preseason games on any season-ticket package, lost games are lost revenue.

That revenue is a small slice of the financial pie for teams in comparison to network television money or corporate partnerships. As ESPN reporter Kevin Seifert noted, adding an additional playoff game could offset the revenue.

Beyond the revenue, though, some coaches feel they need preseason -- all four games.

"Do I feel that way?" Saints coach Sean Payton asked. "Yes, just because of how much we're restricted in the spring and quite honestly, what we're restricted in training camp. I know the challenge oftentimes is that fourth preseason game, but I can't think of a season here where that fourth preseason game didn't mean something to a handful of players that were in it."

Fangio, who has spent more than three decades in the NFL, isn't quite ready to do away with preseason games, either. Asked if he could see a scenario when joint practices could replace preseason games in an NFL summer, he said: "I hope not. If you're into developing players, preseason games are important. If you're not into developing players, then they're not."

ESPN NFL reporters Nick Wagoner, Lindsey Thiry, Todd Archer, Mike Triplett, David Newton, Adam Teicher, Rich Cimini and Brady Henderson contributed to this report.