Posted by ESPN.com's Paul Kuharsky

INDIANAPOLIS -- Can you plop guys into the complex Indianapolis Colts’ offense, ask them to interpret all that Peyton Manning does at the line of scrimmage, request they sort through the defense’s attempts to throw them off and expect them to be in the right places and contribute?

Dallas Clark has said it took him four years to feel fully comfortable with the nuances of the Indianapolis passing offense.

But here, with Marvin Harrison gone and Anthony Gonzalez out, the Colts asked second-year wideout Pierre Garcon, who played his college ball at a place most football fans haven’t heard of, and receiver Austin Collie, whose career is four games old, to make significant contributions.

Sunday at Lucas Oil Stadium as part of a 34-17 handling of the Seattle Seahawks, they both did.

Manning and coach Jim Caldwell are happy, of course, but they want to temper the excitement, too.

"I'm really pleased with the plays they're making, I think all of us are,” Manning said before earning a couple of laughs at his postgame news conference. “We just have to kind of take it step by step before we crown them quite yet. Sometimes we have to control you guys from blowing the egos up a little bit. It's a learning process. We have played two unfamiliar opponents these last two weeks. Getting into the division starting this week, it's important everybody's on the same page."

“It bodes well for them having a game like this but the thing is, they are still a long ways away,” Caldwell said. “I think it takes time to mature within this offensive scheme. They have been making some plays and everything is working well for them. There are still a lot of things for them to learn, a lot of things yet to be discovered for them. But they are the kind of guys that will keep working until they get it.”

Garcon had a 25-yard reception on the Colts’ first possession, pulling in a great throw by Manning into a tight window between Kelly Jennings and Jordan Babineaux. On the second possession, the second-year man from NCAA Division III Mount Union broke open for a 35-yard catch up the left sideline on a third-and-3 that seemed like trouble as defenders closed in around Manning.

They were key plays on his team’s first two touchdown drives.

Collie’s six catches included a beautiful diving touchdown grab of a 21-yard ball Manning put over his left shoulder just three seconds before half. Collie ran a pattern to the back right corner of the end zone and gained a step on Travis Fisher.

The ball from his first NFL touchdown secured as part of a win, Collie credited the leadership of Manning, Reggie Wayne, Clark and Jeff Saturday as instrumental in helping the young guys emerge.

“Considering that Gonzo’s been out with an injury, I think that’s something that Pierre and I just try to concentrate on -- making sure that there is not that big of a drop-off,” said Collie, a rookie from BYU.

The two have attained a certain status with those veterans Collie listed. Get on the field with the Colts, you are expected to perform. While coach and quarterback work to temper expectations, others can take more leeway giving you credit immediately following an outstanding effort.

“This is kind of a new time, a new era I guess, with losing Marv and Gonzo to an injury. They’re getting called upon early to make plays for us and they are doing a fantastic job,” Clark said. “They’re not getting frustrated with getting to know everything. They are high-pressure situations. It’s just really cool to see those young guys make those plays so early.”

“I’m happy for them, that’s what we’re going to need from them,” Wayne said. “We’re going to need them to learn quickly and play as veterans. That’s kind of the cards that we were dealt. Those guys need to respond fast and they’ve been doing that.”

Seattle didn’t produce a winning effort on any front.

But I am guessing if defensive coordinator Gus Bradley was told his unit could limit Wayne and Clark to a combined 14 catches for 154 yards and a touchdown, he would have said OK and taken his chances with the rest of Manning’s unproven targets.

Joseph Addai, Collie, Garcon and Donald Brown combined for 16 catches, 200 yards and the other passing touchdown.

Indianapolis, now 4-0, visits the 0-4 Tennessee Titans in Week 5. If Cortland Finnegan (hamstring) is still out, the Titans could have a rookie corner, Jason McCourty, as a starter and another rookie, Ryan Mouton, in the slot as their nickelback

Selling out to shut down Wayne and Clark and taking their chances with everyone else would seem the way to play it, but the Colts have shown in the first quarter of their season they have alternate means to hurt a defense.

“We’ll see how people play us, but [Garcon and Collie] are capable of making plays. And I am sure that they have probably in other people’s minds -- I’m talking about people we play against -- gone from nonentities to guys that you’ve got to at least think about," Colts president Bill Polian said. “So we’ll see how things go.”

Said Manning: “I know every game that we’ve got two young receivers in there. There is never a moment in practice or a game where you can kind of relax or breathe and say, ‘Oh, he will know this. … Pierre and Austin have not seen a lot of these looks. So every game is a learning experience.”