These 2 rookies looked like starters in 49ers' first preseason game

You could be forgiven for not paying much attention to an NFL preseason game. After all, in most cases, starters don't even play snaps. That was certainly the case for the San Francisco 49ers on Saturday night against the Tennessee Titans, where several players missed out on game action.

However, if you're committed to talent evaluation, it does provide a fantastic opportunity to get a glimpse of the potential of the team's younger players, and recently added rookies in particular.

Let's take a look at two in particular who impressed, with a possible honourable mention.

Dominick Puni

All eyes were on Dominick Puni heading into the game, and with good reason. Not only is he that rare high-draft pick lineman (something the 49ers have often been reticent to do), but with Spencer Burford out injured and Jon Feliciano seemingly also dealing with medical issues, Puni was the player who had been taking the starting snaps at the right guard position.

It's probably best for all parties if Puni works out. After all, the right guard spot has been a running sore for the Niners for quite some time, rotating through several players who have either been mediocre veterans (like Feliciano) or younger players who couldn't hold the spot (like Burford).

In many ways, that missed block in overtime in the Super Bowl was a microcosm of the 49ers' issues at the position.

Happily, then, Puni looked as advertised on Saturday night, and possibly better, anchoring well in pass protection, particularly on quarterback Brandon Allen's deep third-down drop-back on the opening drive, but also playing solidly in the run game, helping running back Jordan Mason to gain a lot of positive yards and score a touchdown on the opening drive.

As Lombardi suggests, the key thing Puni needed to show was improvement as a run blocker. Strangely, for a college offensive lineman, his pass blocking was thought to be his strength when he entered the draft.

More than anything, he looked settled and like he belonged on the field. Niners offensive line coach Chris Foerster openly speculated about Puni's lack of experience potentially being a barrier to him starting in a press conference a few weeks ago, but this performance might have calmed those nerves, given he looked comfortable in the scheme.

It seems like he's making good strides, and given the time he's spent practicing and playing at the position this summer, and the ongoing injury issues for his competition, it definitely wouldn't be a shock to see him in the starting five linemen in the 49ers opener against the New York Jets.

If he nails the spot down for Week 1, will he stay there?

Malik Mustapha

Safety Malik Mustapha was perhaps the viral star of Saturday night --his Exocet-like hit on fourth down drew some oohs and aahs -- but there were many positives for Mustapha to take away from his first NFL game.

The viral moment was one of only two tackles he made on defense in the game, the other being a thunderous hit in kickoff coverage, which is his better route to playing time this year. Given how often tackling technique is poor in the NFL preseason, particularly from players lacking experience, his solidity and downright nastiness at the point of attack won't have gone unnoticed.

What will have pleased defensive coordinator Nick Sorenson more, though, is the mental side of the game. Mustapha slotted in with very few mistakes and was even seen visibly correcting rookie cornerback Renardo Green's assignment and positioning at times.

For a safety in particular, who has to read the offense and break on the ball, that mental aptitude is a very positive sign. While it's hard to see him getting the start over veteran safety George Odum for Week 1, assuming the still-injured Talanoa Hufanga doesn't make it, Mustapha should have at least put himself in contention for more playing time with a solid game.

There's a reasonable argument that, given the position and his immediate taking to the defensive scheme, Mustapha may be the 49ers rookie most ready to start, if required. His instincts on Saturday actually reminded one at times of his safety stablemate, Hufanga, who parlayed good preseason form into increasing playing time in his rookie season.

Mustapha will certainly be one to watch as the season continues on, particularly as Hufanga's contract and health situation remain uncertain, and Odum is best suited to a special teams role.

Honourable mention - Tatum Bethune

While it's beyond unlikely that linebacker Tatum Bethune will start, and he even has an uphill climb to make the roster, it's worth shining some light on a good performance. He jumped off the film several times throughout the game, which allowed him to end up leading the team in tackles with eight (five solo, and three assists).

As with Mustapha, though, the pleasing thing was the instincts shown to make those plays. Bethune was rarely out of position throughout his time on the field and often found himself at the point of attack. In an NFL era of coverage linebackers, Bethune looks like an old-fashioned thumper, taking on blocks and disrupting running lanes wherever possible.

It's difficult to pinpoint his potential, but he looked a lot like another undersized, lightly-regarded 49ers linebacker: the infamous one-season wonder that was Chris Borland.

Bethune wouldn't have been on most people's radar before this game, and has been barely mentioned throughout the offseason, but his play on Saturday has at least put him in the minds of most fans, and possibly the coaching staff too.

Which 49ers rookies impressed you the most?

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