Blaine Gabbert on the spot early

For way too long, the NFL offseason revolved around the games being played by lawyers and negotiators.

Thanks to the settlement of the lockout, football is back -- and the preseason kicks off with five games each on Thursday, Friday and Saturday. The Jets close out the first week with a Monday night game against the Houston Texans.

No one can predict the quality of the product. Coaches no longer have two-a-days to grind their players into shape. The first part of camp was more conditioning than preparation. New players have had only a week to work with their coaches.

Nevertheless, football is back. Here are the 10 things to watch in Week 1 of preseason.

1. Gabbert's early test: David Garrard's sore back opens the door for Blaine Gabbert to get more snaps for the Jaguars in Thursday's road game against the New England Patriots.

Garrard will sit out, giving Gabbert a chance to get a good portion of the snaps. Jaguars coach Jack Del Rio brought back veteran Todd Bouman on Tuesday to give the team an extra arm. Gabbert has impressed the coaches with his physical presence. He has a strong arm. He's mobile. But he's also raw and will be going against Bill Belichick's talented defense.

2. New-look Pats D? Perhaps the more interesting aspect of the Jaguars-Patriots game is whether Belichick will show off his new base defense. Since acquiring Albert Haynesworth in a trade with the Redskins, the Pats have been loading up on defensive linemen, tipping off that they are switching to a 4-3 scheme. Since late last week, they've added four defensive linemen -- ends Mark Anderson and Andre Carter and tackles Shaun Ellis and Gerard Warren.

Belichick looked at the available free-agent crop of linebackers, including Matt Roth and Channing Crowder, but opted to go with the strength of the market. Pressuring the quarterback from the linebacker position has been a problem the past couple of seasons. By loading up with defensive linemen, the Pats can try to win those battles at the line of scrimmage from a 4-3 scheme.

3. Eagles' crowded secondary: In Thursday's Philadelphia Eagles-Baltimore Ravens game, coach Andy Reid will get a chance to show off his new secondary. What will be interesting to watch is how he fits Asante Samuel into the scheme now that the Eagles have added CBs Dominique Rodgers-Cromartie and Nnamdi Asomugha.

Against three-receiver sets, will Samuel play inside and try to pick off passes? Will Rodgers-Cromartie sit when the Eagles use only two corners on the field? With 13 new additions through free agency and a trade, the Eagles are one of the most interesting teams to study this preseason.

4. Broncos' QB debate: Tim Tebow may not take center stage in the Broncos-Cowboys game Thursday, but his play will draw the most attention. As expected, Tebow has struggled in camp. The lockout prevented him from working with coaches during the offseason. He's listed No. 2 on the Broncos' depth chart behind Kyle Orton.

New coach John Fox didn't draft Tebow, so he has fresh eyes to judge the quarterback debate in Denver. Fans love Tebow. The new coaching staff, though, may feel safer with Orton, who is an efficient quarterback. A bad performance by Tebow could get the fans thinking the same way as the coaches.

5. McNabb's fresh start: Donovan McNabb will make his debut for the Vikings on Saturday in Nashville against the Tennessee Titans. His blindside protection will be an issue because the Vikings cut left tackle Bryant McKinnie, who was overweight and had a scary cholesterol level during his camp physical. Guard Anthony Herrera is recovering from last season's knee surgery, so McNabb will have to adapt to an offensive line under repair.

But at least he's away from Washington. The experience with the Redskins was horrible for him. He lost his status as elite NFL quarterback and, even worse, lost the starting job to Rex Grossman. He hopes to rebound with his new team.

6. Redskins' QB situation: Speaking of Grossman, some interesting things are brewing in perhaps the most understated quarterback battle in the league. Coach Mike Shanahan tabbed John Beck as the projected starter during the final day of April's draft. But Beck has been slowed by a groin injury. Grossman was re-signed a week into camp, and he could jump ahead of Beck and Kellen Clemens if he has a good preseason. The Redskins will host the Steelers on Friday night.

7. Giant issues: Plenty of questions haunt the New York Giants, who play at Carolina on Saturday night. There is a hole at tight end after Kevin Boss left for the Oakland Raiders and free-agent signee Ben Patrick retired. The Giants considered signing Plaxico Burress but lost him to the Jets. They are debating what to do with Steve Smith, the talented slot receiver who is coming off microfracture surgery.

To get under the salary cap, the Giants had to make major offensive line changes; they released guard Rich Seubert and center Shaun O'Hara. Defensive end Osi Umenyiora is unhappy with his contract and wants to be traded. Coach Tom Coughlin has some giant headaches.

8. Newton's debut: The other interesting part of the Giants-Panthers game will be the NFL debut of Cam Newton. The Heisman Trophy winner isn't expected to win Carolina's starting QB job at the beginning of the season, but he has surprised coaches with how well he is picking things up.

Jimmy Clausen has been running the first team, and the Panthers signed Derek Anderson as a veteran insurance policy. The feeling in Carolina is that Newton has done well enough to merit getting a chance to play at some point this year. A good preseason could speed up the timetable.

9. Can Kolb kick-start Cards? The Cardinals made a bold move giving up a second-round pick and Rodgers-Cromartie to acquire QB Kevin Kolb. On Thursday night, coach Ken Whisenhunt will have his first chance to see Kolb in action in a game against the Raiders.

Kolb has a strong arm and good mobility. What will be interesting to watch is how Whisenhunt structures the offense. Will he use more running formations with Kolb, or will he try more three- and four-receiver sets? The Cardinals believe that Kolb is the key to making them a playoff contender again.

10. Sanchez shorthanded? The Jets have lofty goals, but they've had to redo their receiving corps. Gone are Braylon Edwards, Jerricho Cotchery and Brad Smith. An ankle injury may prevent Burress from making his Jets debut, so QB Mark Sanchez will have to get to know recently signed Derrick Mason, who probably will work out of the slot.

Coach Rex Ryan believes the Jets are going to the Super Bowl, but the offense is undergoing change. Shonn Greene takes over as the workhorse running back. The receiving corps is older and maybe a little less athletic.

John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com. Follow Clayton on Twitter