The quarterback position is always an area of interest and especially this season, as there is a legit competition going on between Blaine Gabbert, Luke McCown and David Garrard. We all know Gabbert will be taking over the job eventually, but training camp will decide whether or not it's in November or September.
With David Garrard's back tight, there's a solid chance that he won't play and Gabbert will get extra work with the starters. Watch how he handles the pass rush and throws on the run.
There is one legitimate position battle occurring on the offensive line- left guard. The candidates will be rookie Will Rackley and veteran Jason Spitz. The team would like Rackley to win the job and through the first 10 or so days of camp he's winning.
Another position of concern to watch is right tackle. Although Eben Britton will be the starter barring injury, he has been very shaky in camp and looking back on film, he's been very shaky since his arrival in Jacksonville. Watch how Britton handles the Jaguars pass rushers.
Outside of three players who are roster locks in Mike Thomas, Cecil Shorts and Kassim Osgood, the Jaguars have a wide open competition for the likely two remaining spots.
Cecil Shorts has looked great in camp, but there really hasn't been any difference between the rest of the group of wideouts. It's very possible that an undrafted free agent could find their way on the roster and the best bets are Armon Binns and Jamar Newsome. They will compete with Jason Hill and Jarett Dillard.
The Jaguars have another wide open roster competition, especially at defensive end. Austen Lane and Aaron Kampman look like roster locks, and Aaron Morgan has been very solid in practice. After a rough start, Larry Hart has come on in the past few days and undrafted free agents Marc Schiechl and Odrick Ray have impressed. Watch and keep track of which players can collapse the pocket tonight.
Another player to watch is last year's third-round pick, D'Anthony Smith. Smith has struggled thus far in camp after trying to recover from a ruptured Achilles.
There isn't going to be much you can learn from the linebackers in tonight's scrimmage. We know the starters will be Daryl Smith, Paul Posluszny and Clint Session. Since new free agents weren't allowed to practice with the team until Thursday, these players will likely be a little out of sync in the scrimmage.
There will be a couple openings at linebacker available, as Russell Allen appears to be the only backup that's a lock for the roster. Undrafted rookie Scott Lutrus is in the mix, as well as Michael Lockley and second-year guys Jacob Cutrera, Kyle Bosworth, Alvin Bowen and Slade Norris.
It would appear as if the Jaguars are set with their starting cornerback duo of Rashean Mathis and Derek Cox. Looking past the starters is a nickel competition between veteran Drew Coleman, David Jones, William Middleton and rookie Rod Issac. Coleman and Issac will likely win the nickel and dime jobs respectively.
The Jaguars are still trying to figure out their starters at safety, as free agent Dawan Landry can play both free and strong, but is better as an in the box strong safety. Talent-wise, the Jaguars best duo would be Landry and Courtney Greene, but they may be lacking in coverage ability. Rookie Chris Prosinski will earn a roster spot, but will not be likely ready to play this year. Terell Whitehead, Michael Hamlin, Matt Estrada and Don Carey will compete for one spot.
Although it's impossible to watch every position, these are some of the battles and issues you should keep track of.
Charlie Bernstein is the NFL Insider for ESPN 1080 and 1040 in Orlando/Tampa and the host of "The Sports Crunch" on the Aquarius 7 Broadcasting Network (national), and Editor-in-Chief of Sports Media Interactive, covering multiple teams in the National Football League, NCAA, and National Basketball Association. Charlie covers the Jacksonville Jaguars for FoxSports and has been featured on the NFL Network and Sirius NFL Radio. Charlie is also a member of the Pro Football Writers of America. You can follow Charlie on Twitter @nflcharlie