1. Battle at Center

When assistant head coach/offensive line coach Tom Cable addressed the crowd at last week's Seahawks Town Hall, he referred to the battle to replace Max Unger at center as a five-player competition. That was somewhat surprising, because up to that point Lemuel Jeanpierre and Patrick Lewis were the only two centers to see significant first-team action during Organized Team Activities. On Tuesday, however, it became evident that Cable was serious about an open competition when Drew Nowak took the majority of the first-team reps at center.

"It's probably got the most competition to it," Cable said of the center battle. "Drew's doing a good job, (Kristjan) Sokoli's doing a nice job and Lem and Patrick are competing their rear ends off, so when we get to camp, it should really be quite a battle. That (position) certainly has the most uncertainty."

On Nowak, Cable said, "The fact that he's been here the whole year, so he's gotten trained, and now we're starting to see an offensive lineman develop. He's just kind of earned the right to go in there now and be a part of that competition."

Cable hopes to start narrowing the center competition down in training camp and sort things out, "somewhere in the preseason. When? Who knows? I think it's going to show up pretty quickly though."

Sokoli, a sixth-round pick who played defensive tackle at Buffalo, is making quick progress at his new position, Cable said.

"He's on it right now," he said. "I wouldn't say he's behind. He might even be a little bit ahead. A ferocious competitor, so I think that's given him the opportunity to stand there and kind of fight his way through this learning process, and it's a ton. It's a big hill to climb, but I think he's doing well."

2. The depth at receiver is impressive

Douglas McNeil III made one of the better catches of practice, a leaping grab in the end zone on a pass from R.J. Archer. Not long after that play, undrafted rookie Deshon Foxx came up with an impressive sliding catch, a play he finished by jumping up, having not been touched, and sprinting for the end zone. That those two players stood out Tuesday, two players fighting an uphill battle to make the roster, highlights the solid depth Seattle has built at receiver heading into the 2015 season.

Third-round pick Tyler Lockett was the big offseason addition for Seattle, but he's not the only reason the Seahawks are better at receiver than they were a year ago. Chris Matthews development, highlighted first by his role on special teams, then by a huge Super Bowl performance, has him poised to take on a bigger role in 2015. McNeil III's 6-foot-3 size and athleticism makes him an intriguing, if still unproven prospect, and we still haven't even mentioned Doug Baldwin, Jermaine Kearse, Ricardo Lockette or last year's draft picks Paul Richardson and Kevin Norwood.

3. Even All-Pros have to earn their stripes

A week after Jimmy Graham dominated in the red zone, Seattle's new tight end had a harder time catching passes, both because of good coverage and errant throws. And every time a pass intended for Graham didn't find its target, defensive players made sure to let him hear about it in a loud but playful way. Those barbs, just like Graham's emphatic spikes last week, are all just a part of his initiation process with a new team.

"He has to go through his growing pains," cornerback Richard Sherman said. "He has been in the league long enough, but he has to go through the gauntlet to get the respect he wants."

4. Graham isn't the only red-zone threat at tight end

While the defense kept Graham largely in check Tuesday, one tight end did do some damage in the red zone, with Cooper Helfet catching a pair of touchdown passes. Helfet and Anthony McCoy saw a bit of extra action with Luke Willson limited. And it's worth remembering that while Helfet has just two career touchdown catches, both have been rather impressive.

5. Cliff Avril and Christine Michael were back

After missing earlier OTAs following the death of his father, defensive end Cliff Avril has been back in action this week, and immediately got back to making plays, including a knocked down pass at the line of scrimmage that he nearly turned into an interception.

Even with Avril back, however, Ryan Robinson continued to earn significant playing time, taking snaps with the first-team nickel defense.

Also returning to action was running back Christine Michael, who was out last week for undisclosed reasons. With Marshawn Lynch absent and Robert Turbin recovering from offseason hip surgery, Michael got the bulk of the first-team carries.