It's early, but Lions might have filled their pass-rush void

ALLEN PARK, Mich. -- Some notes, thoughts and observations after the fourth day of Detroit Lions training camp.

1. Rotating left tackle: With both Cyrus Kouandjio and Greg Robinson back and healthy enough, the two have been rotating at left tackle fairly regularly with the first team against the defense. Typically, Kouandjio has taken the first few reps before being spelled by Robinson. For now at least, it seems like a pretty even two-man competition between them, although there's a long way to go. Chemistry with Graham Glasgow and performance in preseason games should dictate who starts there. A player who still hasn't taken a left tackle rep that I've seen with the first unit is Cornelius Lucas, who has been primarily a second-team right tackle. So this could be a two-man competition only.

Robinson seemed comfortable, for now, with splitting reps as both he and Kouandjio are learning the offense after arriving on the same day -- the last day of minicamp. Robinson said the biggest difference from his previous team, the Rams, has been terminology and some scheme things.

"It feels good to get the defense in front of you and get guys moving, but watching it helps a lot also," Robinson said. "The reps are very valuable, so you have to make the most out of it. I think [at] some points, when guys give you something that you haven't really seen against the plays that we're running, it becomes challenging. But [you've] just got to adjust and pick it up as best as possible."

2. Another good day for Anthony Zettel: The second-year defensive end looks so much faster this year, particularly during one-on-one drills with the offensive line. His jump off the line of scrimmage, at least at this early juncture, looks to have improved dramatically, as has his overall speed. There was never a questioning of his athleticism -- after all, he has tackled dead trees, thrown a baseball 94 mph and participated in MMA training. But he seems to have found a way to channel that athleticism into football. He's the guy, perhaps more than any other nonrookie on the roster, that I'm curious to see in preseason games against other teams. He's worked a lot with the first-team defense with Ezekiel Ansah out, and if what he's flashed during camp translates against opponents, the Lions might have a shot at finding their third edge rusher.

"He's working at it all the time. He's trying to take care of all the little things, so we see some improvement already," Lions coach Jim Caldwell said. "So we'll see what happens when we get into ballgames. But he knows what he's doing. He has a good feel for it, and we expect to see obviously some improvement over last year, for certain."

There's a definite opening for a pass-rusher in the Lions defense, and it appears Zettel will get the first real chance at it.

3. Barry's back: Barry, of course, is Barry Sanders, who showed up at training camp Wednesday wearing one of the new Lions jerseys (No. 20 Sanders, obviously) as part of his new job as an ambassador for the club. He was spotted chatting with some people when rain and thunderstorms forced practice inside. Sanders, though, did not speak with media. Also in attendance Wednesday was former Lions linebacker Chris Spielman.

4. The return drops: The Lions seemed to work more on kick returns than punt returns Wednesday -- and the sign for that was both where the players lined up on the field and also who was in the mix. Instead of Golden Tate and Jace Billingsley, Dwayne Washington was in the group of returners along with TJ Jones, Jared Abbrederis, Keshawn Martin and Jamal Agnew. The player to watch here is Agnew. He looks clean fielding the ball, has experience with the role of returner from college and has enough speed and vision to move up the field fast.

Washington was a potential return candidate last year, but the job went to Andre Roberts, now with Atlanta. On Wednesday, Washington didn't look too smooth in the role. He dropped one kick and appeared to bobble another before holding on to it. When he caught it cleanly, it was obviously that his size and speed were valuable, as he had strong cuts in the drill, which didn't allow tackling.

5. Marvin Jones looks sharp: This was in particular during the one-on-one drill with cornerbacks, which took place from the 3-yard line into the end zone on Wednesday. After a first rep on which Darius Slay had a pass breakup, he stuck with Jones, who had beat D.J. Hayden badly on two other reps into the corner of the end zone. Jones then adjusted well to a ball on Slay to make the touchdown catch. We'll have more on Jones and what he's done to try and make himself a more valuable receiver Thursday morning, but he looked a lot like the player the Lions saw during training camp and the first four weeks of the season last year.

This and that

For the first time at training camp, the Lions had music at practice. First song was, unsurprisingly, Kid Rock's “Bawitdaba.” Kid Rock is a big Lions fan. Also played: Guns N' Roses, DJ Khaled and what I believe was KB's "I Believe," featuring Mattie of For Today. Much of the track is "I Believe That We Will Win," the USA soccer chant -- perhaps some subliminal messaging for the Lions. ... The Lions will have their first off day of training camp Thursday before returning to practice Friday morning.