They've got plenty of company.
The two All-Americans are among a record 65 players who have been declared eligible for the April draft, a field that also includes Heisman Trophy winner Robert Griffin III and runner-up Andrew Luck as the top quarterbacks. Counting Richardson, the top three Heisman vote getters are all leaving early to start cashing NFL paychecks. The NFL released its official underclassmen list Thursday.
Despite a rookie wage scale established in the new collective bargaining agreement, the number of players choosing to leave school early tops the previous record of 56 set last year. NFL draft consultant Gil Brandt isn't sure that's a good thing.
"I don't think it's surprising, because there's so much more activity by agents today, telling these young guys to come out of school," Brandt said. "Consequently, I think that's the whole story.
"What a lot of them have told kids is that they're going to be drafted high, or that they've seen the draft list and they're going be second-round picks and things like that."
Plus the LSU and Alabama trios.
Brandt said he had thought the rookie wage scale might have the reverse effect.
He said some players like USC's Kalil are likely Top 5 picks, making leaving early an economic no-brainer. Others, like South Carolina cornerback Stephon Gilmore, could have potentially improved their stock with another year in college, Brandt said.
"I think in a lot of cases guys that are coming out, it's a mistake," he said. "I was really happy to see (Oklahoma's) Landry Jones and (Southern California's Matt) Barkley and those guys stay in school.
"The people who stay in school and finish up seem to have a better chance of succeeding for a longer period in the National Football League."
In some cases, they can also improve their draft stock considerably, something that's not quite as profitable under the rookie wage scale but is still worth a nice chunk of change.
"He stayed for his full time at Nebraska," Brandt said. "Had he come out a year early, he would have probably been drafted the lower part of the first round. He stayed in school and wound up being the second pick in the draft.
"It was probably worth $15 million to him at that time."
Suh signed a 5-year deal worth $40 million guaranteed and up to $68 million.
Quarterbacks Jones and Barkley aren't the only stars who are staying put. Claiborne's fellow All-America cornerback and Heisman finalist Tyrann Mathieu is just a sophomore while Wisconsin running back Montee Ball - fourth in the Heisman voting - is coming back for his senior season.
So is Alabama's Outland Trophy winner Barrett Jones.
Tide teammates Richardson and Kirkpatrick had young children as impetus in their decisions.
"You have to have some kind of background for playing this game," Kirkpatrick, who has a 5-year-old son, said after announcing his decision. "This is not a game that you just wake up and play. It has to mean something. You have to have something that's going to drive you and make you play 100 percent.
"I feel like my son is the anchor of all that."