This is the litmus test.
The following two days could give us the clearest preseason barometer for how the San Francisco 49ers might fare in 2017. If you asked any player or coach, they'd tell you that these joint practices against the Denver Broncos hold more value than any of the four exhibition games.
It's all about volume. Pierre Garçon and the first-team offense might get two-to-three series on Saturday night. That group will get far more reps in practice. Wednesday's session will be in full pads and players will wear shorts and shoulder pads on Thursday. This marks the third straight season in which these teams have held joint practices.
Here are three matchups to watch over the course of the next two days.
1. 49ers Passing Game vs. Broncos Secondary
Aqib Talib and Chris Harris Jr. are two of the NFL's premier cornerbacks. They'll provide a great challenge for Hoyer, Pierre Garçon and Marquise Goodwin. Those three will look to get going after a sluggish two series last Friday against the Kansas City Chiefs. A few explosive plays in the passing game would help put those three-and-outs behind them.
In particular, the matchup between Talib and Garçon should be entertaining. Both players are known to mix it up a little bit on the field.
2. Joe Staley and Trent Brown vs. Von Miller
Remember last year when Miller said that Brown had the potential to be one of the NFL's best tackles? That's what put Brown on everyone's radar as a player to watch in 2016. The lineman went on to start all 16 games a year ago and now has much greater expectations for his third season. For those who like to say that "iron sharpens iron", reps against the three-time All-Pro should be something that Staley and Brown are looking forward to.
3. Rashard Robinson vs. Demaryius Thomas and Emmanuel Sanders
Robinson started his preseason against Tyreek Hill last Friday. He'll get another speed threat in Sanders. Then Robinson will go to the opposite end of the spectrum and cover the 6-foot-3, 229 pound Thomas. The 49ers second-year corner has been adamant that he wants to go toe-to-toe with the NFL's elite. Sanders and Thomas fit that bill. Sanders has three straight 1,000-yard seasons, and Thomas has put together a run of five such campaigns.