ALLEN PARK, Mich. -- Ernie Sims, the ninth overall pick in this year's NFL draft, signed a five-year deal with the Detroit Lions on Sunday, leaving only two of the top 10 choices unsigned.

Sims agreed to terms Saturday night and reported to the Lions on Sunday after getting a call late Saturday from his agent, Todd France, telling him the deal was done.

"I was lying down and trying to get some rest, just in case I would be practicing," the linebacker from Florida State said. "I had mixed feelings -- I really wanted to be out here, but I didn't want to be under this sun."

The 6-foot, 221-pound Sims, who missed the first two days of training camp, finished his collegiate career with 200 tackles, seven sacks for 61 yards and 21 tackles for loss. He made an immediate impact Sunday, cracking fellow rookie Brian Calhoun with a forearm to the head on his first play.

"That felt good," Sims said. "I couldn't unload on him like I wanted, but it was nice to get a lick in."

Sims signed at about the same time Reggie Bush, the second overall pick in the draft, agreed to terms with New Orleans. That leaves only safety Donte Whitner of Buffalo, No. 8 overall and Matt Leinart, Bush's Southern California teammate taken by Arizona two picks later, unsigned.

Sims, known for his speed, showed quickness during the hot, humid morning session where temperatures were in the high 80s. But defensive coordinator Donnie Henderson didn't get carried away.

"He's great, but we have to keep one thing in mind," he said. "This is Ernie's first practice, and it is everyone else's fifth. He's got fresh legs."