Monday's combine observations

The combine shifted to defense Monday, and the momentum of fast times and good performances continued.

As the combine runs its course, scouts, coaches and general managers have to be pinching themselves. With 98 underclassmen entering the NFL -- including 85 at the combine -- the more players work out, the better the draft looks.

Looking at the first day for defense, the line stock appears to be as deep and as rich as it is at wide receiver and along the offensive line. Linebackers didn't disappoint either.

Here are the five things we learned Monday at the combine:

1. The draft's biggest tease: South Carolina defensive end Jadeveon Clowney continues to be the biggest tease of the 2014 draft. The tease continued Monday. He looked like the best athlete in the draft -- as expected -- by running a 4.53-second 40-yard dash, fastest among the defensive linemen. He vowed to run a sub 4.5 40, and handheld times had him around 4.48. For a 266-pound defensive end, that's phenomenal. During his final two years at South Carolina, Clowney was pointing to 2014 to be the top player in the draft. The tease started in 2013 when he appeared to hold back his effort. He had only three sacks as a junior, and even South Carolina head coach Steve Spurrier conceded he wasn't the greatest practice player. The mystery continued Monday when he elected not to participate in all of the defensive line drills. Once again, Clowney left questions about how dedicated he is to football. For talent, though, his abilities are off the charts.

2. If Michael Sam drops in draft, it won't be because of his announcement: Though he was impressive talking Saturday, Sam didn't wow anyone with his workouts Monday. He ran a 4.91 40. His vertical was also disappointing at 25½ inches. Before the combine, Sam announced he was gay. He held up well during his Saturday interview with the media. Sam did say that he was asked only football questions during his interviews with teams. Everyone is rooting for him to be judged as a football player. Based on his numbers Monday, though, he might not go as high as he would like. Because he is considered more of a situational pass-rusher, his value is between the fourth and sixth rounds. A good workout could have put him into the third round. But the lack of speed and explosiveness could push him down the draft board. He showed he could be projected as a pass-rusher and core special-teams player.

3. It's great to be big and fast: A strong group of defensive linemen looks even more impressive after what it did Monday. The most impressive interior lineman was defensive tackle Aaron Donald of Pitt. At 6-0¾ and 285 pounds, he ran a 4.68 40. Let's put that in perspective. Donald ran the same time as Johnny Manziel, who weighs 207. Imagine that kind of speed and explosiveness along the line. He could be the ideal 3-technique tackle. Another big winner was Timmy Jernigan of Florida State. At 6-1 5/8 and 299 pounds, Jernigan, a nose tackle, ran a 5.06 40. Defensive tackle Ra'Shede Hageman of Minnesota was also a stud in the 40. At 6-5 7/8 and 310 pounds, Hageman ran a 5.02. Coming into the combine, Donald, Jernigan and Hageman all were considered lower first-round picks. They may have edged toward the middle of the first round with their times.

4. The outside linebacker race is compelling: Some people believe Khalil Mack of Buffalo could be in consideration for the top pick in the draft. Though he did everything Monday to enhance those thoughts, Mack has a challenger -- Anthony Barr from UCLA. Watching them compete is like watching Team USA play Russia in Olympic hockey. They might have to go to a shootout to determine the winner. Their 40-yard dashes were nearly identical. In handheld times, each clocked at 4.66 in his first run. On the second run with handheld times, Barr did a 4.63 and Mack was at 4.62. Once the electric times were sorted out, Mack had a slight edge with a 4.65 to Barr's 4.66. Barr is 6-4 7/8 and 255 pounds. Mack is 6-2 5/8, 251. Watching these two compete for the top outside linebacker spot should be a blast.

5. There weren't many disappointments: None of the top linebackers or defensive linemen who ran really hurt his draft stock, but a few might want to run again. Kony Ealy of Missouri is a first-round defensive end, but he might have to try to improve his 4.92 40. No worries for Notre Dame defensive tackle Louis Nix. He did a 5.42, but because he weighs 331 pounds, no one cares about his speed. He's an anchor along the defensive line. C.J. Mosley, considered the draft's top inside linebacker, didn't run. Neither did Dee Ford -- one of the top defensive ends -- who was medically scratched.