If Cooper Rush is a lock, where do the Cowboys go light?

Stephen A. laughs off Cowboys' backup QB competition (1:43)

Stephen A. Smith isn't worried about who will back up Dak Prescott in Dallas since Prescott isn't as injury-prone as Tony Romo was. (1:43)

FRISCO, Texas -- As the preseason winds down, so much of the process for teams is attempting to find ways to fit square pegs into round holes.

Not necessarily with their scheme and players’ abilities, but with the composition of the roster. In this week’s Five Wonders, the top wonder is just that.

Away we go:

• At the start of training camp, very few folks would have had Cooper Rush on the Dallas Cowboys' 53-man roster. The undrafted quarterback has played remarkably well in the first three preseason games. He’s likely found a spot on the 53-man roster now, and the Cowboys split some of the second-team work between Kellen Moore and Rush on Monday. But I wonder where the Cowboys will go light elsewhere in order to fit the third quarterback on the 53. Instead of four tight ends, do they take three? Five wide receivers instead of six? Six linebackers instead of seven? Five cornerbacks instead of six? Arguments can be mad that the player given up at those spots would have more of an impact in the season than a No. 3 quarterback, but having a backup of the future in Rush is an inviting possibility. Just know, however, that you can’t have it all when you put together the 53-man roster.

• I wonder if seeing Trevor Siemian win the Denver Broncos' starting quarterback job has the Cowboys breathing a sigh of relief that they did not make the trade up for Paxton Lynch in the 2016 draft. Jerry Jones regretted it mightily after the draft because the Cowboys felt like Lynch had the most upside of any quarterback available. Broncos coach Vance Joseph mentioned command of the offense, ball placement and decision making as reasons he chose Siemian over Lynch. When you think about what Dak Prescott is really good at, it’s command, ball placement and decision making. This isn’t to say Lynch wouldn’t be better with the Cowboys and learning from Scott Linehan and Wade Wilson, but it also reinforces how much draft success is predicated on, frankly, luck.

• I wonder if the injury suffered by Odell Beckham Jr. on Monday, be it ankle or knee or whatever, will have an impact on what the Cowboys do with their starters Saturday against the Oakland Raiders. The New York Giants receiver appears to be OK, but it certainly had to be scary for the Cowboys’ season-opening opponent to see him go down like that. So do the Cowboys put Dez Bryant, Tyron Smith, Sean Lee, Jason Witten and Prescott on ice? I don’t think you’ll see the Cowboys go that far, but do they come out for the second half? It seems wise to cut the preseason to two games given the lack of playing time starters see now anyway. Oh, and while we’re at it, cut the prices of the tickets to these exhibition contests as well. Paying regular-season prices for these games is shameful.

• I wonder if cornerback Duke Thomas has a spot on the 53-man roster sewn up. Like Rush, nobody would have had him on the roster when camp began, but he has done a lot better since the pads came on and made the most of the opportunity presented when Jourdan Lewis, Marquez White and Chidobe Awuzie suffered hamstring strains that limited them in practice. In the last week, Thomas has added kickoff returns to his duties. The coaches are trying to find different things for him to do so he can bring value to the roster. He could get caught in that aforementioned wash because of Rush’s roster spot, but he has put himself in the mix and could be needed early in the season if those hamstring strains of Lewis and Awuzie don’t clear up soon.

• The Raiders will be the third opponent the Cowboys will see in the preseason that they will also see in the regular season. The game plans against the Arizona Cardinals and Los Angeles Rams were next to nothing, so they didn’t give away any information. Saturday’s game is the most regular-season like in terms of playing time and game planning. But I don’t wonder if the Cowboys will hold back on what they show Saturday on both sides of the ball. These teams don’t meet until December. So much will change between now and then that whatever game plan is thrown out Saturday will have little impact in what happens on Week 15.