Kellen Mond was one of the last Vikings players to leave the practice field Wednesday. The rookie quarterback stayed late to work with two receivers and even seemed to be running through a play in his head as he made hand gestures during a moment by himself.

To the delight of his head coach, Mond also said he's making a "conscious effort" to speed up his tempo when he's operating the offense.

"At times I think too much on the field," Mond said. "I just want to go out and play football. That's really my entire goal for this game [Saturday]."

Mond's preseason debut vs. Denver this past weekend was a predictable mess, considering he had little practice time beforehand after missing 10 days because of a positive COVID-19 test.

Mike Zimmer's postgame critique sounded particularly blunt and harsh. Zimmer lamented that Mond operates in "slow motion," then gave a cryptic answer when asked why Mond wasn't asked to throw more passes and added a parting shot by calling his rookie a "laid-back guy."

"He's kind of got to get out of his shell a little bit," Zimmer said. "If you're going to be the quarterback, you have to do those things."

Told of that comment after the game, Mond said, "I don't necessarily know exactly what he means by that on my personality."

Two theories in trying to understand Zim's motive: He was still frustrated that an unvaccinated player missed extended practice time. And this was merely a case of a coach sending a stern message to a rookie quarterback about how things need to be done.

"Sometimes I kind of say things to try and help guys," Zimmer said this week. "They don't always like it, but so be it."

Mond's response to criticism has pleased his coach. Coincidence or not, Zimmer praised Mond for having his best practice yet Monday and noted that he is moving at a faster pace.

There undoubtedly will be more hiccups and hard moments to come. This amounts to a redshirt season for Mond, a chance to sit and learn behind Kirk Cousins and refine his game on the practice field. But that conversation should remain open-ended.

Nothing guarantees that Mond's grooming period lasts only one season. It's still so early in his development that nobody can predict with any degree of certainty when, or even if, Mond will be ready to take over as the starter. The expectations tied to a quarterback taken in the first round vs. the third round are entirely different.

"He needs practice repetition," offensive coordinator Klint Kubiak said. "He was out multiple days with COVID and he just needs the reps."

Cousins described being a young NFL quarterback as a "long process" and a "roller coaster." Good days followed by bad days. Progress followed by mistakes.

"There is no minute that it suddenly flips," Cousins said. "You just keep stacking up the days."

The quandary facing the Vikings right now is that they have two young, unproven quarterbacks behind Cousins, and they're running out of days before the season opener.

Jake Browning played so poorly in the preseason opener, which included throwing a pick-six, that he called it a "lost opportunity."

Cousins has been strikingly durable throughout his career as a starter, but it would be unwise to just assume good health at any position. Plus, the COVID concern will linger if Cousins remains unvaccinated.

Does the team really feel comfortable entering a season with either Browning or Mond as the backup? After what we witnessed in the preseason opener? With an otherwise veteran roster that is under pressure to get to the playoffs? No way.

Saturday's game against the Indianapolis Colts could either help solidify one of them in the backup role or compel the organization to sign a veteran with NFL experience before the opener.

Mond's development requires some patience regardless. The roller-coaster ride is just beginning.