If there is a good thing about the preseason, it is when teams can come together and work for two or three practices before a game and give coaches and scouts the opportunity to really evaluate their squad.

It’s a reality check. When you practice for two or three weeks with only your players, you are put into a false sense of security. The ills of the team aren’t exposed as much when you practice with yourself, but when you play games, those faults are put front and center.

The Cowboys and Chargers had two productive days of work before lining up last Sunday night. The Chargers have always been one of my favorite teams to follow because I have always respected the way they built their football team, so the fact that Jason Garrett and Norv Turner were able to put this together was positive for both clubs.

*Defensively for the Cowboys, Chargers quarterback Philip Rivers was going to put a great deal of pressure on this defense. He gets rid of the football quickly and he is accurate in doing it. Vincent Jackson and Malcolm Floyd were going to also challenge Orlando Scandrick, Alan Ball and Bryan McCann on the outside.

In the Friday practice, Scandrick was at his best in the way he was able to defend Jackson in the one-on-one drills and team periods. Scandrick was able to use his quickness to stay with Jackson and fight him for the ball in the air, which is tough to do because of Jackson’s height and his ability to use his body to shield the defenders.

In the game, Scandrick got put in a tough situation where he drew Jackson in the slot. Rob Ryan dials up a blitz, leaving his secondary in man coverage. As the play develops, Scandrick turns his body sideways in an effort to keep Jackson from running inside on him, thus taking away the chance of Rivers trying to work the ball inside on the “hot.” Jackson goes vertical with Scandrick, who now is in a sideways pedal, trying to run with him. Jackson has separation on Scandrick, who realizes what is happening to him in the route. Jackson has now taken his route up and across the field and with no help, Scandrick is trying to cover as much ground as he can as fast as he can. As the Ryan blitz develops, Rivers, his backs and offensive line have picked it up across the board. Rivers floats a perfect pass to Jackson, who is slightly ahead of the scrambling Scandrick for a big play.

There is a reason I break this play down. There will be times where Ryan will lock his secondary up in man coverage and gamble that he will be able to get his rush home before the quarterback will be able to get rid of the football. There could be some real struggles for this Cowboys defense when Ryan doesn’t blitz and has to rely on pressure just from his front.

DeMarcus Ware is an outstanding player and was able to get a sack when the coverage downfield was solid and he beat Randy McMichael, but there were times in this game where Ware was single blocked by backup tackle Brandyn Dombrowski and didn’t get any type of pressure. Ryan will have to move Ware around to help him, because if he doesn’t, teams will scheme him all day.

The best pressure the Cowboys were able to get on the Chargers was when they brought the extra rushers. How Ryan creates pressure without blitzing will go a long way to shaping how this defense plays this season.

*Much has been made about the left guard situation for the Cowboys. I am going to be honest here and say that the time that Montrae Holland has missed might have been a blessing for this club.

With Holland out, the club has managed to rotate a group of young players through that position. The latest to start at left guard was Bill Nagy. This was an interesting position me to watch because I thought that Nagy did a solid job at center. Nagy looked more than comfortable playing fill-in wherever he was needed.

Nagy played well. Technique-wise his pulls were good, stayed on his feet, hit the target and able to secure his man. There was a play where Jason Garrett called a stretch play going left and Nagy was able to shove the end down to Doug Free, helping him secure his block, then work up inside to handle the linebacker.

In pass protection, I only saw one time where Nagy struggled. He was driven into Tony Romo’s lap when he wasn’t able to anchor down and be stout in the front of the pocket. In offensive line play, guards are responsible for the depth of the pocket while the tackles handle the width. Guards have to keep the front of the pocket clean so the quarterback has the ability to step forward.

Backing up Nagy in this game was last week’s starter against the Broncos, David Arkin. This game was not as easy or clean for Arkin, but it was not a total bust either.

Arkin will always play with the effort and intensity, but he just doesn’t have the upper or lower body strength when defenders take him down inside on the rush. Needs to be tighter on his pull, was too aggressive trying to help Costa secure his block and not able to work outside to prevent a sack.

On the final play of the game, Arkin gave up a pressure on a spin move, which caused Stephen McGee to have to back pedal and make an off-balance throw. Arkin did do a job on sorting out a twist stunt and there were times in the running game where he was able to secure his man.

Looking ahead, I feel like that Holland will be the starter when he is healthy enough because the club knows what they have in him. I don’t agree with it at all, because it limits what Garrett can do with this scheme. Holland’s lack of mobility is a liability. Garrett is trying to use his offensive line by pulling, down blocks and getting them to the edge -- all things that Holland struggles with.

The Cowboys are running the ball better because the athletic ability of this line with the combination of the blocking of the tight ends. Felix Jones is hitting the holes quicker because this line is doing a better job of getting hats on hats. Holland can play with power, but he just doesn’t have the movement of Phil Costa, Nagy and Arkin.