LOS ANGELES– Somewhere on a dry-erase board at Oxnard, Calif., or on a notepad or piece of paper among the front-office personnel, exists a short list of available free-agent quarterbacks.

Now, don't expect anything to get erased or thrown away after Saturday night's game in Los Angeles, butt those veteran quarterbacks shouldn't be holding their breath for the Cowboys to call anytime soon.

Yes, it was just one game for Dak Prescott. Check, it was one fantastic game for the rookie quarterback, who made his debut as the starting quarterback in front of 89,140 people and the world watching on ESPN as football returned to Los Angeles after a 22-year absence.

Prescott's first snap came later than expected, considering Lucky Whitehead returned the opening kickoff for a touchdown. But once he finally got in, Dak stole the show, outshining the Rams' return to L.A., the debut of No. 1 pick Jared Goff and even Whitehead's electrifying start.

By the middle of the first quarter, Prescott was the man of the hour and rest assured it'll stay that way for a week or two. In fact, by halftime, Dak was the No. 1 trending topic on social media … move over Rio.

I've been on record all summer as saying that Jameill Showers looked a tad better than Prescott through the offseason practices and even into training camp. OK, that's done, although Showers did have the play of the night with his pocket-escape in the third quarter.

But clearly, it was Dak's night. Prescott is not only the second-best quarterback on this team, he proved he needs to continue to get every opportunity to become Tony Romo's backup.

Applaud the Cowboys' brass for holding off on signing a veteran just yet. It's not a given they won't eventually go down that route, but if last year taught us anything, it's that maybe you don't invest in a veteran until you're sure he's the best option. Personally, Brandon Weeden outplayed Matt Cassel in their time on the field last season, but once you send a future draft pick to Buffalo, you pretty much have to play the guy you acquired.

So had the Cowboys signed Nick Foles or traded for a veteran, he'd be playing right away in these preseason games, and we'd never get to see what Prescott could do against top competition.

Here's some more props to give: Offensive coordinator Scott Linehan did a superb job of getting Prescott ready for this once-in-a-lifetime event. But Dak couldn't have looked calmer in making his NFL debut – preseason or not.

Linehan and the offensive coaches took care of Dak early on, giving him rather simple underneath throws and screens, followed by some back-shoulder passes, including a touchdown to Dez, who certainly looked to be back to his 2014 form with a couple of great catches.

Back to Dak, he was getting himself into rhythm, completing every pass other than a couple of dropped screens by usually steady tight end Geoff Swaim. But you could see the confidence grow in Dak later in the first half, especially when he ripped a crossing route to Brice Butler over the middle, sending the rope-like pass to his left for a 22-yard gain.

If there was a word that kept popping up in my mind to describe Dak, it was "smooth." He was smooth all night, whether it was at the line of scrimmage, changing the plays, or standing in the pocket. One of my favorite Dak plays of the game was on third-and-26, just before halftime. The drive was getting stalled by penalties, but Prescott avoided a blitz and found 14 yards of running room that set up a field goal.

I know he played three years at Mississippi State, but he showed a lot of poise on that play. Instead of trying to get the first down and making a low-percentage play, Dak took what was available and got the three points.

Fortunately, my second-quarter tweet wasn't taken too seriously when I referenced another rookie quarterback making his preseason debut some 15 years ago. Back then, the Cowboys were so high on Quincy Carter, that all it took was a couple of touchdown passes against the Raiders to convince Jerry Jones and the team that he was the guy. The next week, they cut veteran Tony Banks and went with Carter, who clearly wasn't ready for that role.

Obviously, this Tony is safe from any such move. Dak was sensational, but certainly not good enough to think about him moving up the depth chart anytime soon.

But he's not moving anywhere from that No. 2 line, either. And after one game, why would he?