IRVING, Texas – When the Cowboys gave Dez Bryant jersey No. 88 in 2010 they did not try to shy away from comparisons to and expectations of Michael Irvin and Drew Pearson. Jason Garrett has long said Irvin’s greatest attribute was his ability to keep working when everybody else tired. Irvin would run route after route after route long after everybody left Valley Ranch, and a lot of the time Garrett was throwing the passes. As Bryant begins his fourth season with the Cowboys, the receiver is trying to incorporate more Irvin into his game.

IRVING, Texas – When the Cowboys gave Dez Bryant jersey No. 88 in 2010 they did not try to shy away from comparisons to and expectations of Michael Irvin and Drew Pearson. Jason Garrett has long said Irvin’s greatest attribute was his ability to keep working when everybody else tired. Irvin would run route after route after route long after everybody left Valley Ranch, and a lot of the time Garrett was throwing the passes. As Bryant begins his fourth season with the Cowboys, the receiver is trying to incorporate more Irvin into his game.

Ed Werder talked briefly about DeMarco Murray's durability with Fitzsimmons and Durrett on ESPN Dallas 103.3 FM today. Murray has missed nine games because of injuries in his brief two-year career. In comparison, Emmitt Smith missed a total of seven games in his career with the Cowboys and none his first two seasons. Tony Dorsett missed just 10 games in his career, none his first two season,s and three in the first five years of his career. You could say, well, Dorsett and Smith are Hall of Fame players, and durability is one reason for their success.

IRVING, Texas -- When the Dallas Cowboys drafted Gavin Escobar in the second round of the 2013 NFL draft, it seemed like 2012 sixth-round pick James Hanna was a forgotten man. Hanna, a Flower Mound product, displayed some promise toward the end of the 2012 season. It seemed the Cowboys found a carbon copy of Hanna in Escobar, a slender pass-catching tight end. Did the Cowboys forget about Hanna? "I'm pretty confident in myself and I feel like I have a lot to bring (to the team and) a lot of different aspects to the game, and (Escobar) does too," Hanna said.

IRVING, Texas – Tony Romo wants to take part in the June 11-13 mini-camp. There is no way the Cowboys should let him. To quote Ricky Watters: For who? For what? Romo had a small cyst removed from his back in April and has been limited in his conditioning work for most of the offseason. He has only recently done some light jogging to go with work on the bike and elliptical machines. He has not done any sprinting. The first pass Romo throws in 11-on-11 drills has to come in Oxnard, Calif.

Part four of Cowboys Nation's week-long chat with offensive analyst Rich Musinski looks at the challenge of running a play sheet on game day.

Cowboys Nation: We just talked about time during a week and during a season. The clock is always ticking during a game.  You have limited time between series and once a series starts, between individual plays.

You need to have a play chosen when you begin, and they you have to see how it goes.  When you're standing there with your play sheet, how much time do you have to make a decision?  And do you always have a couple of plays in your mind?  Do you think, "I want to run play A on 1st down and if it does well, I'm going to run play C, but if my pass is incomplete, for my run goes for no gain, then I need to have play X as a fallback?

Rich Musinski:  A lot of guys I know will try and script out their first 25 plays, and think this is the first play I'm going to run, and then run play two and then if things work out well, play three.

But that's all based on success.  As you said, if play one works, I'll move to the next play on my script, and if that goes well, then I move on to my next option.

A lot of these coordinators you see have play sheets bigger than some of the guys on the team.  And they're broken down by down and distance. You'll have stuff that's for 1-and-10, 1st-and-5, 1st-and-long.  They'll have all their plays broken up.

These are there to help you if your script gets broken.  Say you make a call on 1st-and-10 and you're sacked, so now it's 2nd-and-16. You flip the sheet over to your longer pass plays.

Still, the plays have to be called in very quickly.  It's much easier now with the radios and head-sets, that helps so much, as opposed to even the college level where they have to be signaled in and all the players have to be in sync.  You do have some different systems like Oregon's, where they hold a bunch of cards.  You don't see that much in the NFL.

As far as the play calling goes, you know what you want to run.  You've seen the film. You know which matchups you want to create.  You know who you want to get the ball, on 2nd-and-long, 2nd-and-short.  You have a general idea.

You also have other coaches helping you.  They're focused on different parts of the game.  One might be watching the DBs and he might see how they're reacting to certain plays. They'll say, "this looks good, or when you try this, so-and-so goes this way, so try this."  You have other people helping you out.

CN:  I want to bend the discussion towards the Cowboys for a bit. This is a team that in recent years has had problems with penalties.  They take a lot of procedure penalties.  They take holding penalties.  I imagine as a play caller a team like that has to be a nightmare.  You know they're going to take a handful of penalties and you don't know when they're going to show up.

RM:  And one of them will always come at the most inopportune time.  There might be that big call that gets you out of a jam, and all of a sudden there's a yellow flag on the ground.

It does get tough.  It does get frustrating.  I know even for me, you make a good call and boom, you get a holding call.  You get a false start, and next thing you know you're 2nd and 25 and I don't have plays for 2nd and 25.

False starts... you can control false starts.  That's a you problem. You can control you moving.  Now, holding?  Ah, sometimes you get beat, you have to hold a guy.  But false starts is a self-discipline thing.

Those things are drive killers.  You take a couple and you're back in your own territory instead of being on the edge of scoring position.

CN:  As a play caller, how much of the challenge is maintaining your calm?  Part of your job is keeping your team focused, so you can say, "we scored a touchdown, but we have to overcome a couple of penalties at the beginning of it."

RM:  Sure.  That's why the quarterback is so important. He can keep teams from panicking. And your job is just calling your game. Even if you get a holding and its 1st-and-20, you still have three downs and you can chip away at it.  It does take a lot to keep the coaches and the team focused.

CN:  Between drives. Let's say you come out and something is not working the way you planned.  How much adjusting can you do during halftime?  Can you make serious changes, or are you just making small tweaks?

RM: I would say it's more minor things.  It's not like you come in at halftime and say, "we're throwing the game plan out, and we're just drawing up a bunch of new plays."  You come in at half-time, and everybody who was upstairs is able to come in and sit down with the players.

And you talk it over.  You might say, we were looking for this defense and instead they're running this defense.  So instead of running a play this way, we're going to run it the other way.  As you said, it's a matter of tweaking.   You're still going to have your plays, and instead of cutting in one place, you cut here.  And instead of cutting off a route at a certain point, you do it at another one.

Even up front, you're expecting a certain front and you're getting another one. But there are a lot of adjustments.  If you're a successful staff, you have to make these adjustments constantly during a game.

Next:  Where does the blame lie when something goes wrong, and what makes a quality coordinator?

IRVING, Texas – Among the reasons why Brian Urlacher decided to retire was the fact that he could say he played for the Chicago Bears and for the Chicago Bears only. In this salary-cap age, that is a difficult thing to do. Emmitt Smith's playing career ended in Arizona. Jerry Rice's ended in Seattle. Troy Aikman and Michael Irvin were able to be “one jersey” players, in part because of injuries. Aikman wrestled with the idea of returning not long after he stepped away but decided against it.