RENTON, Wash. -- Seattle Seahawks cornerback Richard Sherman missed his second straight practice, which means he's in at least some danger of missing a game for the first time in his NFL career.

How much danger depends on how you interpret Seahawks defensive coordinator Kris Richard, who was ambiguous Thursday on the subject of Sherman's availability for Seattle's home opener against the San Francisco 49ers, perhaps intentionally so.

"We're just being cautious with him," Richard said. "We'll see whether or not he's going to be available. I know he's preparing as if he is and he will be available. I think it'll be a coach's decision."

Sherman has been an iron man since entering the NFL as a fifth-round pick in 2011, appearing in every one of a possible 97 regular-season games plus 12 more in the playoffs. Richard was asked how different it would be for him as the defensive coordinator if he had to consider the possibility of Sherman not playing, given that it's never happened in his NFL career

Richard said with a smile: "I'm not even considering that. It's never happened here."

Sherman played all 82 defensive snaps in Seattle's opener against the Green Bay Packers, so it was a mild surprise when he was listed on the team's injury report with a hamstring injury. Sherman routinely gets what are known as veteran days off once a week, but it's much less common for him to sit out consecutive practices like he did Wednesday and Thursday.

Hence, the uncertainty about his status for Sunday.

So what would the Seahawks do without him?

While there's no precedent to point to, the most logical adjustment would be to have veteran Jeremy Lane take over Sherman's usual spot at left cornerback. Rookie Shaquill Griffin would start in Lane's place at right cornerback and newcomer Justin Coleman would handle nickelback duties. That would make Neiko Thorpe the fourth cornerback, should he be needed.

As Seattle's third cornerback, Griffin was already going to play extensively in his first career start last week against Green Bay. But he ended up playing more than anticipated -- 77 of 82 defensive snaps -- after Lane was ejected in the first quarter. Lane's absence had a ripple effect beyond forcing Griffin into the No. 2 role. It also pressed Coleman (41 snaps) into action at nickelback, which is usually Lane's role when Seattle goes with five defensive backs.

Seahawks coaches and teammates have raved about the poise of Griffin, a third-round pick. He showed it Sunday while being thrown at repeatedly by Aaron Rodgers.

"He did a great job. He honestly played just like he's been playing. He'd been playing very consistent throughout the preseason and took it right to game time, which is really a marvelous thing to see for the coaches," coach Pete Carroll said Monday. "He was able to maintain his mentality and his focus and stay disciplined and aggressive and he did all of that and he got challenged, too. He had many opportunities there, so really pleased with his progress."

The Seahawks were equally pleased with how Coleman fared, especially given he had just arrived a week earlier in a trade with the New England Patriots.

"He did very well. We were kind of hoping to give him some time to catch up, but he jumped in and had to go immediately in and showed really good coverage skills in the man-to-man stuff as well as the his own stuff and understanding of what we wanted," Carroll said of Coleman. "He played really aggressively and got after playing his guy and it was a really nice day's work for him. He also contributed in special teams, so to be able to do that that is a good showing for a first time out."

Even if Sherman ends up playing Sunday and making that contingency plan moot, the Seahawks have confidence that Griffin and Coleman can step in again.

"No question," Richard said.