NFLDraftScout.com rates Ellis and Davis as first-round picks, with Jackson and Thomas second-rounders.
"If any one of those guys had come out early, they wouldn't have been nearly the status that they are," Carroll said.
Mike Mayock, draft analyst for the NFL Network, has gone out on a limb for now, and rates Ellis ahead of Louisiana State defensive tackle Glenn Dorsey.
"I don't think there's any way we'd be talking about him as a top-10 pick had he come out last year," Mayock said of Ellis. "The difference in dollars between, pick a number, the No. 6 pick in the draft and the No. 20 pick, is millions and millions. I think he made a very smart move coming back."
Mayock currently has Ellis as his second-rated player, while NFLDraftScout.com has him third overall.
THE ONE WHO LEFT
Trojans offensive lineman Chilo Rachal was the one Trojan who did leave with eligibility remaining. But he has good reason.
According to Rachal, his mother, Veronica Pickett, has a tumor in her stomach, but no insurance. His father, Charles Rachal, has two hernias, but no insurance.
Said Chilo Rachal, "I would have loved to come back and gotten my degree and played another year under Coach Carroll. At the same time I had to do what's best for my family. I love my mother and I'm going to do the best thing I can to put her in a better situation. She's my motivation every day I wake up."
Rachal said his father has continued working in construction -- "My dad's 64 but he still carries the wheelbarrows up and down the stairs every day to take care of my mother" -- despite the hernias and bad knees.
Concluded Rachal, "I don't like my dad working like that with the injuries he's dealing with. But at the same time he's the one making money to take care of my mother."
LONG-ING TO PROVE ... AND IMPROVE
Jake Long could have been a first-round pick in 2007, but he returned to Michigan, along with Mike Hart and Chad Henne, with the goal of writing a proper ending to his college career. In Long's first three seasons, Michigan lost its final two games -- against Ohio State and three consecutive bowl games.
Long played right offensive tackle and moved to the left side as a junior.
"I just really wanted to improve my pass sets," Long said of senior-season goals. "Two years ago was my first time on the left side. I wasn't really used to the pass sets on that side. I got a lot more fluid this year with my pass sets ... working on my hands, certain rush moves."
Long wasn't perfect as a senior. The Buckeyes beat Michigan again. And Long allowed a sack to OSU's Vernon Gholston, another likely first-rounder in '08. It was the first sack charged to Long since he surrendered one as a redshirt freshman.
A self-projected NFL left tackle who modeled his game after Patriots Pro Bowler Matt Light, Long (6-feet-7, 313 pounds) expects pro defensive ends to challenge him every down.
"I think playing against the D-ends in this league. They are fast and they are strong and they are huge," he said.
WAITING FOR APRIL
Count Jacksonville Jaguars vice president of player personnel James Harris as one executive who would like to see the draft occur before free agency. The start of the league year is Feb. 29, when free agents can begin to be signed.
"Ideally, it would be great if the draft came first," Harris said. "That way, you can evaluate your team, make your picks in the draft, then see what you need. Sometimes, veteran players don't play as well for you as they did for the team they're leaving."
GETTING SOME DISCIPLINE
Virginia offensive lineman Brendan Albert attended Hargrave Military Academy before Virginia, and credits his time there for creating some discipline in his life.
"There was no freedom," Albert said. "They told you when to eat, when to sleep, when to go to the bathroom. But it gave me discipline and prepared me for the discipline in coach (Al) Groh's program. It benefited me greatly."
As for Groh, Albert said, "Coach Groh runs a pretty tight program. That helped me out significantly with this whole process. That made me a tough player, a tough guy. He builds a program that helps you have good character."
-- "We got off the plane from Arizona and started draft meetings right away. I guess we'll celebrate in June."
-- Giants general manager Jerry Reese on how long he was able to celebrate the team's Super Bowl victory.
-- "I kind of did. But I was undersized for a baseball player."
-- Louisville PK Art Carmody, who measured 5-8, 177 at the Combine, on considering pro baseball over the NFL.
Howard Balzer is Senior Writer for NFLDraftScout.com. Editor Jeff Reynolds contributed to this report.