ENGLEWOOD, Colo. -- This week of Broncos training camp may have started with Peyton Manning goofing around a bit, but as the team's second preseason game approaches, No. 18 is as business-like as ever.

As tempers flared a bit during practice, Manning looked on with a small shake of the head.

"I know the coaches are looking for tough guys on their team but there is a difference between being tough and not being smart," he said after practice Tuesday. "...It is a matter of staying disciplined, staying composed under the intense situations."

A group huddle in the middle of practice with Head Coach John Fox calmed things down a bit and the rest of the day was without any scuffles. Outside of the scraps, Fox said he thought the practice was quite productive, just the way his quarterback likes it.

"I had a coach who taught me at an early age of treating practice like a game," Manning said. "To me this is where you become a better football team out here on the practice field. You don't just show up in a game and expect to be a good football team."

After a good showing from the starters against Seattle in the team's first preseason game, another challenging opponent awaits as a good measuring stick this Sunday. But Manning said the team isn't yet preparing for the 49ers schematically, as the offense is "still putting in plays and working on different wrinkles."

"I am just trying to work on good timing, having good comfort, good feel with all the guys and the way they're running their routes," Manning said. "...So that is kind of where my focus is just trying to get on the same page on a chemistry stand point with each guy."

Much of that chemistry has been built through post-practice work with the team's new wide receivers, namely Emmanuel Sanders and Cody Latimer. But Sanders has sat out a few practices in the past week with a slight quad strain and only participated on a limited basis Tuesday. His injury has opened up more opportunities for Manning and Latimer to connect in team drills.

Likewise, the absences of Montee Ball and C.J. Anderson have given undrafted rookie Juwan Thompson more chances to react to Manning's checks at the line and pick up blitzes behind Ryan Clady, Louis Vasquez and Co. In Tuesday's practice, Thompson took his mouthpiece out a few times to confirm his assignment with his quarterback, but again showed he's comfortable in pass protection, stoning T.J. Ward when the safety came up the middle in red zone work. Paired with the progress of other pieces around Manning, the quarterback is happy with what he's seen.

"I do think those guys are studying -- Emmanuel, Montee, these young backs -- I see them studying on their own and let's face it, the cerebral part of the game, to me, is just as important as the physical part of the game," Manning said. "If you don't know what you're doing it is hard to put you in there."

While Sanders is likely to play against the Niners, Ball and Anderson will almost certainly sit out, giving Manning the opportunity to build on-field chemistry with Thompson when the rookie works into the rotation behind Ronnie Hillman. Manning said the team will probably start preparing for San Francisco on Friday.

"It is not like a huge preparation when you are playing against these guys but it is a good test when you're playing against the 49ers," "It's a physical game, it's a team we're going to play again in the regular season, it's a 3-4 defense and so lots of things I think we can get out of this."