ALLEN PARK -- The Detroit Lions have 24 rookies on their roster for Organized Team Activities, and Jim Caldwell was asked about them. Perhaps predictably, he declined to say which had caught his eye the last couple weeks.

"I think that it would be a bit premature for that," he said. "But in terms of learning, it's a smart group of guys that are very, very disciplined -- very, very serious, extremely dedicated to what they do."

Caldwell is right that it's too early to say which rookies are standing out. Remember how good Cole Wick looked this time last year? And he wound up catching just two passes in six games before getting demoted to the practice squad.

With that disclaimer out of the way, there were a few rookies who did catch my eye when Detroit opened OTAs to reporters on Wednesday. Here are three:

LB Jarrad Davis: While Detroit shuttled players on and off the field at a dizzying rate, Davis was one of the rare exceptions. He took damn near every first-team rep at middle linebacker, further evidence Detroit has every intention of giving him the Taylor Decker treatment. Jim Caldwell confirmed as much before practice, saying Tahir Whitehead could still play a big role in 2017, but at another position. Davis looked smooth in the middle, and teammates say he's picking up the scheme quickly, an important marker for his development because he's eventually going to be charged with calling out the plays.

WR Kenny Golladay: Players are in shorts for OTAs, which means nobody's hitting. And that means it's awfully hard to tell who's looking good at certain positions, especially up front. Skill players are a little different story, though, and there was a lot to like about Golladay's early effort. At 6-foot-4, he's impossible to miss out there, providing the kind of size Detroit otherwise lacks at the position. He was known for having terrific hands at Northern Illinois, and indeed, while I saw Marvin Jones drop three passes, and Eric Ebron two, I didn't see Golladay put any on the ground. He's built more like an outside guy by virtue of his length, but how much he plays could be a function of how much he can flex inside, where Detroit must replace Anquan Boldin (for now, anyway), and Golladay got in some work there as well.

TE Michael Roberts: After drafting Roberts in the fourth round, Bob Quinn mentioned he moved deceptively well for a 270-pound tight end. He wasn't kidding. I was surprised at how well he moved for somebody who is bigger than defensive linemen like Anthony Zettel, Armonty Bryant and Kerry Hyder. He's not Eric Ebron, but he can move for a guy that big. Throw in his wide frame and hands that could blot out the sun, and it's easy to see how he led the nation's tight ends with 16 touchdowns. It'll be interesting to see how Detroit deploys him in a pass game that already features Ebron at the position. He has the potential to unlock some possibilities in two-tight end sets.