Best of Day 1 at NFL combine: Top risers, how best prospects fared

— -- Running backs and offensive linemen went through workouts at the NFL combine on Friday, the first day of drills for the top prospects for the 2018 NFL draft.

ESPN NFL draft experts Mel Kiper Jr. and Todd McShay recap how the best backs and linemen?-- including? Saquon Barkley, Sony Michel, Orlando Brown and Quenton Nelson -- fared, and Scouts Inc. analyst?Steve Muench breaks down the under-the-radar prospects who are rising up draft boards. We'll also look ahead to Day 2 of workouts, as the quarterbacks, receivers and tight ends will participate in testing and drills on Saturday.?

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How best prospects fared | Biggest risers | What to watch for Saturday

What was the biggest takeaway from workouts?

McShay:?As I'll touch on below, my biggest takeaway was that Barkley was as advertised. He?crushed his workout and is the clear No. 1 running back prospect. I was also impressed with the athleticism some of the developmental offensive linemen exhibited. Desmond Harrison (Western Georgia) and Brian O'Neill (Pittsburgh), among others, had terrific days.

Kiper:?Barkley was the biggest story of the day -- he was phenomenal. But UCLA offensive tackle Kolton Miller was the second-biggest story of the day.?He?had the best workout of any of the offensive linemen, showing supreme athleticism for a guy in a 6-9, 309-pound frame.?I had Miller in the first round of? my latest Mock Draft, and he showed why on Friday.

How the top prospects fared

Here's how the potential first-round picks from this group performed on Day 1 of workouts:

Saquon Barkley, RB, Penn State

Scouts Inc. position rank:?No. 1

Adrian Peterson had the most impressive combine workout I've seen in person, running a 4.40-second 40-yard dash at 217 pounds, with a 38.5-inch vertical and 10-foot, 7-inch broad jump. Well, Barkley ran the same blistering 40 at 233 pounds and had a 41-inch vertical jump. He caught the ball well during drills, too. I haven't spoken with a person who doesn't like this kid, from spending five minutes or hours with him. He couldn't have done any more today to help his stock, and has put more pressure on the top three teams to select him. A home run day.?--? McShay

Derrius Guice, RB, LSU

Scouts Inc. position rank:?No. 2

Let's be clear: It's Barkley and everyone else in this class at running back. That said, Guice ran a good 40 at 4.49, but at 224 pounds. His vertical jump was a bit disappointing as well at 31.5 inches. Those numbers aren't the end of the world, but they are somewhat alarming. I thought he struggled to track the vertical ball in pass catching a bit as well. His pro day will be important. --? McShay

Sony Michel, RB, Georgia

Scouts Inc. position rank:?No. 3

It was a disappointing performance for Michel. He's the lightest of the top backs at 214 pounds, and while he ran a 4.54 in the 40, I thought he'd be faster based on his game tape. He still has the most meat on the bone to put up good numbers for scouts. Work to do in the process for Michel. --? McShay

More notes on the top running backs:

Of the running back prospects not named Saquon Barkley, Nick Chubb had the most complete workout. His broad jump of 10-8 was 3 inches clear of the historically elite line and his vertical of 38.5 inches surprised me. He quietly put together a very good performance.

Ronald Jones II had a disappointing day, pulling up with an apparent hamstring injury in his first 40-yard dash attempt. I was looking for a better 40-yard time from Rashaad Penny (4.46 at 220 pounds).

Bo Scarbrough?had an awesome day, putting up a 40-inch vertical (second behind Barkley), a 10-foot, 9-inch broad jump (best of RB group) and a 4.52 40 at 228 pounds. He also measured in with 10-inch hands. If his medicals check out, he could be on the rise.? --? McShay

Kolton Miller, OT, UCLA

Kiper's?position rank:?No. 1

Miller's 10-foot, 1-inch broad jump was?the longest by an offensive lineman since 2006. Those are freaky numbers for a 6-9 offensive tackle. Miller 's?4.91 40-yard dash was third fastest?among the linemen, and he also had a vertical jump of 31.5, which was tied for fourth among linemen. He's an athlete, and a team is going to fall in love with his traits.?--? Kiper

Quenton Nelson, OG, Notre Dame

Kiper's?position rank:?No. 1

Nelson is a top-five prospect in this class, and?nothing I saw at the combine made me change my opinion. The 35 reps on the bench press were extremely impressive. He showed some athleticism with a vertical jump of 26.5 inches. Nelson tweaked his hamstring and didn't run the 40-yard dash, but he'll get a chance to run at Notre Dame's pro day. --? Kiper

James Daniels, C, Iowa

Kiper's?position rank:?No. 1

Daniels solidified himself as the top center in this class, but that's because the prospect he was competing with -- Ohio State's Billy Price --? tore his left pectoral muscle?on the bench press. Daniels didn't run the 40-yard dash because of a hamstring injury, but he had a 30.5-inch vertical and ran 7.29 seconds in the three-cone drill, which was among the best of all the linemen. He's athletic and could be picked in the 20s in April. -- Kiper

Orlando Brown, OT, Oklahoma

Kiper's?position rank:?No. 2

Brown was extremely disappointing in athletic testing. At 6-8, 345, we knew he wasn't a stellar athlete. But 14 reps on the bench press, a 19.5-inch vertical jump and a 5.85 40 is poor. He bombed his first job interview in front of NFL teams. Now, it doesn't necessarily mean he will tumble down draft boards. His tape is solid, and he dominated edge rushers in the Big 12. Brown badly needs to bounce back at his pro day and put up better numbers in front of scouts. --? Kiper

Mike McGlinchey, OT, Notre Dame

Kiper's?position rank:?No. 3

There were no red flags for McGlinchey's measureables, as he came in at 6-8, 309. He's just OK athletically -- 28.5-inch vertical; 8-foot, 9-inch broad jump -- and that's why I see him better as a right tackle. His strength is in his technique, when he can drive defenders off the ball in the run game. Like his former teammate Nelson, McGlinchey tweaked his hamstring and didn't run the 40-yard dash. --? Kiper

Connor Williams, OT, Texas

Kiper's position rank:?No. 4

The biggest question on Williams coming into the week was about his medical report, as he missed seven games last season with a knee injury. We don't have the full picture on how healthy he is, but he was impressive on Friday, putting up a 34-inch vertical jump, which was No. 1 among offensive linemen, and running a 5.05 40-yard dash, which was among the best at his position. The 6-5, 296-pound Williams could move back into my Big Board. --? Kiper

Top risers

These are the under-the-radar prospects who opened eyes among scouts on Day 1 of workouts and should move up draft boards:

McShay:?Like Kiper, I'll be watching the QBs, but I'm also interested in the seven wide receivers who measured at 6-4 or above (most since 2003 combine). How many of these guys can show off explosiveness and agility during on-field drills and make scouts and teams go back to the tape?