INDIANAPOLIS -- Three University of Miami players flashed impressive speed at the NFL Combine on Sunday, with Lamar Miller darting to the fastest 40-yard time among running backs and Travis Benjamin tying for the distinction of speediest receiver.

Miller ran a 4.40, beating out Oregon’s LaMichael James, Florida’s Chris Rainey and San Diego State’s Ronnie Hillman, who all finished second with a 4.45.

Miller’s “burst and acceleration are rare,” NFL Network’s Mike Mayock said. But Mayock has questions about how Miller would do in short-yardage situations. Miller is projected as a second-round pick, though he could move into the first.

Benjamin ran the 40 in 4.36 seconds, tying Georgia Tech’s Stephen Hill and Stanford’s Chris Owusu for the top mark among receivers and the highest among all offensive players. “I can take the top off coverage anytime,” Benjamin said.

UM’s Tommy Streeter finished fifth among receivers with a 4.40.

Griffin flies

Baylor’s Robert Griffin III ran the 40 in 4.41, the fastest time for a quarterback since Michael Vick had a 4.33 in 2001. Griffin said he has met with the Dolphins as well as the Browns, Redskins and Chiefs.

Among the numerous other players the Dolphins have met with: South Carolina’s Melvin Ingram (the Dolphins are looking at him at linebacker), Alabama cornerback Dre Kirkpatrick, FSU offensive tackle Zebrie Sanders and UM defensive tackle Marcus Forston.

Jenkins contrite

North Alabama cornerback Janoris Jenkins, who was dismissed by Gators coach Will Muschamp last April after his second marijuana arrest in three months, announced to dozens of reporters Sunday that “I’m done with marijuana forever. I can’t do it, man.” He said he hasn’t used marijuana since leaving UF.

If Jenkins, 23, can convince a team that he has changed his off-field behavior, he could go in the mid-to-late first round. “He’s an elite cover corner,” ESPN’s Todd McShay said.

Jenkins, who has met with the Dolphins, said he has four children, who range in age from three months to three years. Besides the two marijuana arrests, Jenkins also was arrested after a bar fight in 2009.

“I’m a good kid,” he said. “I’m humble. I made a few mistakes. I felt going to North Alabama would humble me. It was a big difference but I learned. I had a talk with my dad. We had to change things I was doing.”

What changes? “I had to separate myself from certain guys and realize there were things I was doing off the field I couldn’t do anymore. It taught me to be a better man.”

Around the combine

• UF’s Rainey could go anywhere between the second and fourth rounds, Mayock said.

He prefers to play running back: “I told [teams] every time they talked to me about receiver, I tell them ‘you’ve still got to have at least a couple plays in there for me at running back.’ ”

Rainey proclaimed, “I have the best jukes in the world” and believes he could be another version of New Orleans’ Darren Sproles, whom he thanked for establishing a “role for all the little people.”

The parents of Dolphins center Mike Pouncey and Steelers center Maurkice Pouncey took in Rainey when he was 16. He lived with them in Lakeland, then followed the Pouncey brothers to UF. “I love them a lot, and they mean a lot to me,” Rainey said.

• The Dolphins are looking for safety help, but Mayock said “this is not a highly regarded class.” He lists Alabama’s Mark Barron as the only first-rounder and Notre Dame’s Harrison Smith as a second-rounder.

Barron, recovering from double hernia surgery, has played free safety and strong safety, but he might be better-suited to strong safety. Smith might be the best free safety in the class.

“It’s very hard for safeties to get in the first round,” Barron said. “That shows the position is being devalued.”