INDIANAPOLIS -- Day 1 of the 2014 NFL combine provided scouts and coaches throughout the league their first opportunity to see in person the talent available for the upcoming draft. Their reaction to the class was euphoric, in large part due to an avalanche of underclassmen whose talent and depth could prove historic.
"I've been doing this for 30 years," said Pittsburgh general manager Kevin Colbert. "This is the deepest draft I've ever seen."
The influx of 102 underclassmen is spread throughout virtually every position, with high-end prospects at quarterback, wide receiver, tight end and the defensive line likely to draw the most buzz this week.
"The whole draft is really strong," new Tampa Bay Buccaneers' general manager Jason Licht said. "Best draft I've seen. It's probably tilted a little more toward offense but it's a strong draft."
The athletic drills for which the NFL combine is so well known don't begin until Saturday so the big news of the first day centered on the measurements of underclassmen offensive linemen and tight ends.
These were the five biggest takeaways of the day:
5. They may have been opponents in the biggest game of the 2013 season but Auburn's Greg Robinson and Alabama's Cyrus Kouandjio both looked like big winners on the first day of the combine.
Robinson, NFLDraftScout.com's No. 4 overall prospect, measured in at a massive 6-foot-5, 332 pounds with 35 inch arms. Kouandjio, was even longer, coming in at 6-foot-6, 322 pounds with 35 and 5/8 inch arms.
Each lack the elite agility to necessarily remain at left tackle early in their respective NFL careers but their length, physicality and aggression in the running game project well as potential right tackle converts. Also working in their favor is the success that the similarly built D.J. Fluker (6-foot-5, 339 pounds, 36 3/8 inch arms) enjoyed as a rookie, after earning the No. 11 overall selection of a year ago.
4. Equally impressive measurements occurred among the interior line, where a trio of Pac-12 juniors certainly looked the part of top 64 picks.
Southern Cal center Marcus Martin came in at 6-foot-3 3/8, 320 pounds. Though Martin currently checks in as NFLDraftScout.com's No. 3 center, his thick build and long arms (34) could help him ascend quickly, just as Travis Frederick did a year ago as a "surprise" first round pick of the Dallas Cowboys.
Stanford's David Yankey sits atop NFLDraftScout.com's guard rankings after a spectacular career playing inside for the Cardinal, but after measuring in at 6-foot-5 5/8, 315 pounds, a move outside to tackle could be in his future. His broad-shouldered frame and physical game is complemented by 34-inch arms.
Yankey certainly sounded like a player ready to take on the challenge of pass protection in the NFL, citing his ability in this role and overall versatility as strengths of his game.
"I think [pass protection] is definitely one of my strengths, being able to go from guard to tackle, really on either side of the line and play all four of those positions," the 2012 winner of the Pac-12's Morris Trophy said.
While Yankey projects well to the NFL in this regard, UCLA's Xavier Su'a-Filo has evidence on tape of his ability to handle this role.
Su'a-Filo measured in at 6-foot-4 and 308 pounds, showcasing the length and relatively slim, athletic frame to project nicely to the NFL as a guard and potential fill-in tackle -- the same duties that helped him take over Yankey's reign as the Pac-12's top offensive lineman in 2013.
3. Given the proliferation of tight ends as legitimate big-play options in the NFL, the size and athleticism of Notre Dame's Troy Niklas, Washington's Austin Seferian-Jenkins and Southern Cal's Xavier Grimble is certain to catch the attention of scouts.
Niklas, who measured in at 6-foot-6, 270 pounds, may have been the most physically-impressive player to walk through the media doors on Thursday. He began his career at linebacker and while a work-in-progess as a receiver, shows off the physicality and aggression one might expect as a blocker.
Seferian-Jenkins weighed in nearly 20 pounds lighter than expected, measuring in at 6-foot-5 1/2, 263 pounds. Scouts knew that he used his unique body control, long arms and soft hands to help him earn the 2013 Mackey Award as the nation's top tight end but his 80" wingspan and 33 3/4" arms helped provide a quantitative illustration of the length which should make him a mismatch against NFL defenders.
Grimble hasn't generated nearly the attention of his conference foe but he may soon after measuring in at 6-foot-4, 257 pounds with huge (10 1/4) hands. Grimble said he received a third- to fourth-round grade from the NFL Advisory Committee but his size, experience in a pro-style scheme and underrated athleticism could make a quiet riser this week.
2. North Carolina left tackle James Hurst entered the 2013 season as a projected early round draft pick, but after suffering an ill-timed broken leg in the Tar Heels' bowl game, he is rehabbing not only his injury, but also his draft projection. Hurst, who grew up just outside of Indianapolis, missed the Senior Bowl due to his broken left fibula and won't be able to work out at the combine this week. However the battle back has been positive. "The rehab is good, coming along fast," Hurst said. "I started walking two weeks ago and it feels good walking around here, feeling normal about it. I still have a week before I'm up and running."
Hurst said he expects to be fully healthy and do a complete workout regimen at North Carolina's pro day on March 25. He understands there will be no second chances; the pro day will be his only chance to impress scouts during the draft process on the field. "It's my full physical audition," said Hurst.
"Most of these guys will do their stuff here (in Indianapolis). But I feel good that I'll do be doing everything at the University I played at and graduated from."
1. While Hurst's recovery is certain to create big news with scouts, it was a former teammate who may have provided the prediction of the day.
North Carolina tight end Eric Ebron (6-foot-4, 250 pounds) isn't as imposing as some of the other gifted prospects at the position but he expects to run fast. How fast? Ebron wouldn't specify his goals but cited a conversation with former teammate Giovanni Bernard as an indicator of his plans for the 40-yard dash. "I'm going to run faster than [Bernard] did, let's put it that way."
Bernard, at 5-foot-9, 202 pounds was clocked at 4.50 seconds in Indianapolis a season ago. Should Ebron beat the Cincinnati Bengals' time, it would be the fastest 40-yard dash run by a tight end of similar size, production and success against top-notch competition at the combine since Vernon Davis was clocked at 4.38 seconds back in 2006.
NFLDraftScout.com Senior Analyst Dane Brugler contributed to this report