The first game of preseason is a weird mix of emotions. For about 15 minutes you get your first chance of the year to see the 49ers play football. Most of the starters are out playing, and while it’s extremely vanilla, it’s still exciting to watch. Then after a drive or two, the faces you recognized are replaced by the ones you don’t. Ugly pigskin ensues.

I don’t mind the vanilla stuff. People who suffered through the Jimmy Raye era would have called the first offensive drive of Thursday’s game adjectives like “impressive,” “progressive” or even “beautiful.” The 49ers moved the ball down the field pretty easily, and although the drive stalled out and resulted in a field goal, there were some positive things to take away.

Colin Kaepernick 49ers preseason week 1Colin Kaepernick

— My first thought when Kaepernick took the field was that he looks bigger than he did last year. Perhaps the added weight will quell some of the fears over injury while running with the ball. He certainly looks more difficult to take down.

— None of the Broncos got a chance to try. The offense didn’t call for any slow-developing routes so Kaepernick was getting the ball off pretty quickly. He got pressured twice, including one attempt by Von Miller that he escaped rather easily by scrambling right and delivering a completion. In the other, Kaepernick simply stepped up into the pocket and ran for the first down.

— The passes he did throw looked accurate: he delivered two impressive zip passes to Anquan Boldin, both of which were placed where only his receiver could catch it. His pass to Vernon Davis in the flat showed what the beat guys have been saying: Kaepernick is developing his changeup. Scary thought.

— Kaepernick has been working on the hard count in practice and he put it to use Thursday. He tried to draw the defense off with a bark on 3rd-and-3, but he had to scramble when they wouldn’t bite.

Offensive Line

— The first player to stand out to me was Daniel Kilgore, who was playing center in place of Jonathan Goodwin. Although it was limited action, Kilgore looked ready to step into the role as a starter. He was solid in pass protection and in run blocking, which included a crushing block on a pull in front of LaMichael James.

— Mike Iupati pulled on a sweep for James but couldn’t establish his block on Miller. No problem for James, who simply outran him.

— Joe Staley was the man to allow the pressure on Kaepernick’s third down scramble. Robert Ayers blew right by him.

— Anthony Davis jumped early for the first team offense’s only penalty, which isn’t shocking because Davis is getting a reputation for those at this point. He also let Miller beat him with a nasty spin move. You take the bad with the good, and Davis brings a lot of that. His form was brilliant, especially in pass blocking scenarios where he anchored the pocket, stepping back and forcing the rusher out with his right hand.

Tight ends

— Vance McDonald lined up in a variety of positions with the first team offense, including the fullback’s spot in an offset I. He set himself there twice (once motioning into it), both blocking from it and running a flat route as well.

— The two knocks on McDonald were his blocking and his tendency to drop passes. I saw what scouts were talking about with the latter — although he wasn’t targeted by Kaepernick, he dropped a few easy passes later in the game. By all accounts he was a beast blocking, though. He’s a very intriguing weapon for the 49ers this year, and I get a sense they won’t be missing Delanie Walker.

— Vernon Davis looked sharp in his limited time with Kaepernick. His 11-yard catch began when he motioned from right to left, setting up one step off of Staley and scraped back across the formation when the ball was snapped. Even with the advantage of already being in position to cover the right flat, Miller couldn’t hang with Davis, who smoked him for the first down.

— Wideout-shmideout. Davis one-on-one with linebackers is still the biggest mismatch in the NFL.

Wide receivers

— Anquan Boldin.

— Oh, I guess I have to be a little more detailed than that. Boldin was incredible, and it’s hard to imagine what this season would be like if the 49ers hadn’t acquired him. He performed as advertised, and 49ers fans have seen a lot of him over the last decade. He won’t smoke you on a fly route, but he’s got some of the strongest hands in the game — an asset he showed off on a third down conversion early in the drive.

— Kaepernick and Boldin seem to have a Kap-to-Crabtreeish chemistry about them already. Health withstanding, this should be a combination we see a lot of in 2013

— The only other wideout to see action with the first team offense was Marlon Moore, who made a nice catch at the end of the drive. It was short of the first down, but it was the best hands we’ve seen from a 49ers receiver wearing #19 in a few years.

Running back

— LaMichael James got reps with both the first and second team offense and benefited greatly from running behind the starting offensive line. For a small running back James still appears to have some tackle-shedding ability, although his bread is still buttered in beating defenders with his legs. He outran Miller on a sweep right and showed some elusiveness on a stretch play left early in the drive.

— James has got to work on those ball control skills. His fumble (which he recovered) in the second offensive drive was all on him. He simply didn’t secure the ball on the handoff from Colt McCoy.

— D.J. Harper came in for one play with the starter and got stopped in the backfield. There will be more on Harper in my upcoming post on the offensive reserves.

— Bruce Miller got stuffed quickly on a fullback dive. It’s okay, though: even Tom Rathman took some time before becoming Tom Rathman.