Although Pete Carroll is an unabashed optimist who has attacked the Seahawks' post-lockout challenges with his usual can-do attitude, even Seattle's perpetually sunny coach realizes Tarvaris Jackson can't possibly be ready to run his offense after just a handful of practices.

At least Carroll's new quarterback won't be the only player learning on the job when the NFL finally returns Thursday with five preseason games. Seattle visits the San Diego Chargers for the first nationally televised game of the year — even if both teams still aren't ready for prime time.

"Tarvaris has been with us for four days, or five days or something, that we've been here together with the whole line and the cadence and the system and the checks and all that," Carroll said. "That's a lot to ask. Other guys are still struggling to catch up right now. We have to look at it a little differently than we have at other times."

After the lockout wiped out most offseason activities and led to short training camps for all 32 teams, the exhibition season could be even more ramshackle than normal. Look for miscommunications, dropped passes, missed blocks, and games with more bloopers than the cutting-room floor at NFL Films.

But the Qualcomm Stadium crowd will see two offenses on opposite sides of the post-lockout spectrum. While the Seahawks undertook an overhaul of their inconsistent offense, the Chargers made almost no changes to their vaunted attack, hoping it pays off in continuity and consistency.

"Every consideration we have about this game is what's best for our football team in September, when we start playing regular-season games," San Diego coach Norv Turner said. "My big emphasis in early preseason games is to start looking at our young guys and see where they're at."

With little time to learn, rookies and newcomers on every NFL team will need every available snap in their four exhibition games to get ready for the season — and Jackson will be under a particularly bright spotlight.

The Seahawks jettisoned Matt Hasselbeck after the three-time Pro Bowl selection's successful decade, determined to rebuild a 7-9 club — which still beat the defending champion New Orleans Saints in a playoff game — with free agents including Jackson, the Vikings' eternal Plan B behind Brett Favre in recent years.

Never mind that Jackson is still learning his teammates' names. He already has been anointed as Carroll's starter, and he knows he's got to start climbing a steep learning curve during his likely brief action against the Chargers.

He's hoping he'll eventually win over Seattle's fans, who usually got steady quarterback play whenever Hasselbeck was healthy in the past decade.

"There have been some good reactions about it, (but) I know there's probably been some bad," Jackson said. "Matt was here 10 or 11 years now, and did some great things here. I heard he was great in the community here. He's been a staple in this community for a long time, and he took this organization to a different level. It's going to be some hard shoes to fill, but ... I'm not trying to take away from what Matt did. I'm just trying to be me."

Jackson actually has a few advantages over fellow free agents around the league who signed after the lockout and weren't allowed to join practices until late last week. Jackson spent the past five years working with new Seahawks offensive coordinator Darrell Bevell in Minnesota, where he also threw to new Seattle receiver Sidney Rice.

Former Chargers backup Charlie Whitehurst and undrafted rookie Josh Portis will relieve Jackson against the Chargers' defense, which added veterans Bob Sanders and Takeo Spikes under new defensive coordinator Greg Manusky.

The Chargers could find the post-lockout transition easier than most teams. San Diego's offense lost just one starter — running back Darren Sproles — from the 2010 unit that led the NFL in yardage, and quarterback Philip Rivers is among the league's best quarterbacks.

Rivers already knows what his offense can do, so he's eager to see what the Chargers' youngsters and newcomers can add to it.

"They're going to get a crash course in the system and the playbook," said Rivers, who started the Pro Bowl last January. "But the best way to continue to learn and grow is to play in the games. This is the time of the year they get extensive reps. I look forward to seeing what some of them do in games. It's always fun to see them go play. You get a feel for them in practice, but there are always guys who don't play, and when the lights go on, you find out a little about them."