Seattle, coming off a preseason-opening 20-19 victory at Dallas last week, plays a Colts team that is making its first exhibition appearance of the season.
The Colts bear little resemblance to last year's team, and not only because of Manning's arrival.
New coach Jim Mora has a staff that underwent major renovation after Lindy Infante was fired on the heels of last year's league-worst 3-13 record.
With newcomers Tom Moore running the offense and Rusty Tillman coaching the defense, Seahawks coach Dennis Erickson doesn't know what to expect.
"It's hard to tell with them because it's a whole new coaching staff, and they haven't played a preseason game," Erickson said.
Manning, who last week signed a six-year contract worth as much as $48 million, will get his first full-contact challenge of his NFL career. Quarterbacks have been off-limits to hit since camp practices began July 24.
Mora plans to use Manning the entire first half, pitting him against a Seattle defense that includes 306-pound, six-time Pro Bowler Cortez Kennedy.
"Whatever time I'm in there, I'm going to try to make the best of it," Manning said.
"I'd like to see him handle the offense with poise," Mora said. "He will make some mistakes, there's no question about it.
"He will have to learn how to rally back from those mistakes. He will be nervous, but I believe he will handle it."
Erickson hasn't been making special plans to deal with Manning.
"Obviously, he's going to be a great player in the league," he said. "But he's a rookie, and I know our guys are going to get pretty excited about playing against him."
In the third quarter, Mora expects to replace Manning with Kelly Holcomb. Bill Musgrave and Jim Kubiak could be used in the fourth quarter.
Erickson is conducting his own test at quarterback. Ninth-year NFL veteran John Friesz started at Dallas last week before turning the ball over to second-year quarterback Jon Kitna.
The two are reversing roles Saturday so Kitna can get a chance playing with the first offensive unit.
Friesz and Kitna are seeing plenty of action because Warren Moon remains mired in a contract dispute and absent from camp.
Moon, who set franchise records for completions and passing yards as the Seahawks went 8-8 last season, is seeking a renegotiated, multi-year contract.
Erickson says the Seahawks have progressed farther in camp this year than they have in his previous three seasons with Seattle.
But there's plenty of room for improvement, Erickson said.
"We need to be more consistent," he said. "We made too many ental mistakes against Dallas."
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