He's had two training camps, two offseasons, a full season and part of another one to become comfortable with coordinator Dick LeBeau's complicated defense. Hood has spent all that time learning from Aaron Smith, who is considered by the Steelers to be their best defensive end in the 29 seasons they've used the 3-4 alignment.
How long he remains a starter might depend not on whether he plays like Smith, but if he resembles the Ziggy Hood who so disrupted offenses while at Missouri. There, he had 15.5 sacks, 22.5 tackles for losses, forced five fumbles and blocked a kick from 2005-08.
And, maybe, whether he is like Keith Gary, Darryl Sims and Aaron Jones. They were first-round flops from the 1980s who played so poorly in the 3-4 that the Steelers went 21 years without choosing a defensive end on the first round until they took Hood.
Some of Hood's teammates know what he's getting into.
"A guy like Aaron Smith has been doing what he's doing for years and years; he's going to be tough to replace," linebacker James Farrior said. "Ziggy has some big shoes to fill. He's a young guy that still needs to learn a little bit."
Only there's no time for that, especially with the other starting defensive end, Brett Keisel, getting over a hamstring injury. If Keisel is ready to play, longtime backup Nick Eason could start rather than Hood, but the Steelers apparently want to find out what they've got in the 6-foot-3, 300-pound Hood.
He hasn't shown much so far, with one solo tackle this season, four last season and one career sack. But it's not unusual for a player to take time to find his way in the Steelers' defense. Outside linebacker Lawrence Timmons, in his fourth season, is only now emerging to become the player he was expected to be as a first-round pick in 2007.
"Aaron's done it for years," Hood said. "I've got to be able to fill in. I won't be able to do the job he can because he's Aaron Smith and he's a great player. But if I can do half of what he does, I'll feel like I've done the job."
So will the Steelers, who need their defensive front to put pressure on Saints quarterback Drew Brees, who averages nearly 290 yards passing per game. In their last two games, the Steelers -- despite winning -- allowed Browns rookie Colt McCoy to throw for 281 yards and Chad Henne of Miami to go 23 of 36 for 257 yards.
"You dream about this chance and this opportunity. It's bad when you get a chance to start because of injury -- you never wish that on anybody -- but now's my chance to maybe go out there and do something," Hood said. "When you've got a guy like Aaron Smith who does his job day in and day out, you can't let that guy get off the field because he pretty much makes the defense. It all starts with him."
Smith, who tore his left triceps tendon against the Dolphins, is one of the NFL's best run-stopping linemen and is an adept pass rusher. Some defensive ends excel against the run or the pass, but it's uncommon to find one who plays both so effectively.
"We've told him, 'Don't try to be Aaron Smith,' " quarterback Ben Roethlisberger said. "Just be you."
Hood, slowed recently by a sore ankle, is eager to find out who he is. He would line up mostly against Saints right tackle Jonathan Stinchcomb, an eight-season veteran who has started every game since 2006.
"It won't be all whoops and hollering if I get rolled up out there," Hood said. "I've got to focus on that. ... But I'm feeling a lot more comfortable and better. Whenever I get in a game, as the game goes on, I feel a lot better. I feel I get stronger at it."
Copyright 2010 by The Associated Press