Each went through the NFL Scouting Combine workout grinder on Sunday, and the results of those workouts were very mixed.
Bosa -- who said he interviewed with 13 NFL teams at the combine, including the Baltimore Ravens, Cleveland Browns, Dallas Cowboys, New Orleans Saints and Tennessee Titans -- didn't do anything to damage his status as one of the elite prospects in this draft class, even though he described it as a "rough, long day."
"I thought Bosa had a good day, not a great day. You could see it when he got to the football drills, I thought he felt more comfortable," said NFL Media draft analyst Mike Mayock on NFL Network's broadcast of the combine. "I was disappointed in his 40 time. I don't think he expected to run in the 4.8-plus. I know I didn't expect to see 4.8-plus. But in the field drills ... I thought he did a great job."
"You can see the difference in explosion," Mayock said.
NFL Media senior analyst Gil Brandt was less concerned about Bosa's 40 time, suggesting that it still keeps Bosa in the conversation to go No. 1 overall.
Spence's draft stock takes a tumble
"What kind of explosion does (Spence) have? You want to be a top-10 pick, Noah, what kind of explosion do you have versus a Khalil Mack, who lit it up here (at the combine) and Von Miller, who lit it up here and then lit up the NFL," Mayock said. "His 35-inch (vertical) was in the ballpark, but his broad (jump) hasn't been and his 40 was disappointing."
So, there's that, and then there's the off-field baggage that Spence carries into his draft evaluation. He went to Ohio State, where he was a first-team All-Big Ten pick in 2013 while starting opposite Bosa (who was a freshman at the time). Spence ran into trouble for failing two drug tests, and was permanently banned from the Big Ten. Spence has spent significant time at the combine, and the Senior Bowl before it, answering for his past and trying to convince teams he's matured.
"The off-the-field red flags are there, and he's had to deal with that all week long," Mayock said.
The 2016 NFL Draft class is particularly deep along the defensive line; there were 64 defensive linemen invited to participate in the 2016 combine. However, much of that talent lingers along the interior of the defensive line. High-powered edge rushers aren't quite as bountiful in the land of plenty. Nearly as important as it is to secure that franchise quarterback is securing that game-breaking pass rusher who can get to the quarterback.
While Mayock said that Bosa is "without a doubt, a top-five pick," Spence's opportunity to make a first-round statement horribly fell flat.
While the momentum train for Spence has screeched to a halt, that of Louisville defensive tackle Sheldon Rankins keeps on rolling.
The workout of Emmanuel Ogbah might vault the Oklahoma State product into the conversation of the draft's top edge rushers.
"I think Ogbah's the guy not on that (top edge rushers) list who made a statement today," said Mayock, who doesn't have Ogbah ranked among his top five edge rushers in the 2016 draft. "When I go back next week, look at everything and talk to some people around the league, I'm going to have to look real closely at Ogbah."
Nkemdiche questions still linger
"The character concerns, that's the big question. The work ethic, the off-the-field character, that's the only reason we're even talking about him going to teams outside of the top 12 (of the first round)," NFL Media draft analyst Lance Zierlein said on NFL Now Scouting Combine Live.
Four of five NFL Media draft experts have Nkemdiche going in the first round -- two as high as No. 19 to the Bills and one as low as No. 26 to the Seattle Seahawks. A fifth, Chad Reuter, does't even have Nkemdiche going in the first round. Instead, it's a second-round projection to the Detroit Lions at pick No. 46.
Somehow, Day was among a number of defensive linemen -- including Bosa -- who went through linebacker drills on Sunday.
Here are some more of Mayock's takes on some front seven defenders at the combine:
» Michigan State defensive end Shilique Calhoun: "He's a high-production player and has a sophisticated array of moves. Teams will look at him as a potential outside linebacker."
» South Carolina State defensive tackle Javon Hargrave: "He has the original bubble butt in this draft."
» Temple linebacker Tyler Matakevich: "All he does is make plays. I will be very interested to see where he gets drafted. This guy is a baller."
Matakevich -- the 2015 AAC Defensive Player of the Year, Bronko Nagurski Trophy and Chuck Bednarik Award winner -- is the classic measurables vs. intangibles draft prospect.
» Ohio State linebacker Joshua Perry: "Perry is like a prototype linebacker from the old day. He looks like a 4-3 SAM to me."
» Alabama linebacker Reggie Ragland: "Ragland has a little bit more agility in the pass game than people want to give him credit for."
Mayock also said that Ragland specializes in "old-school downhill thumping."
» Texas defensive tackle Hassan Ridgeway: "He's going to get caught in that shuffle of all those defensive linemen."
Mayock pointed out Sunday that the defensive line group "is just jammed with potential first round picks ... this is a freaky group." With a position so deep in talent, teams might opt to pass on defensive linemen in the first round of the draft -- even if the talent warrants first-round selection -- to fill positions of need with lesser depth in this draft class.
"Evaluators here know that they can get a quality defensive lineman in the second or third rounds," Mayock said.
» Wisconsin linebacker Joe Schobert: "Watch the Ohio State tape and you'll know he's a football player."