ESPN Sprint Cup

LOUDON, N.H. -- Hendrick Motorsports made it official Friday by announcing that driver Casey Mears would leave the team at the end of the 2008 Sprint Cup season.

"None of us, Casey included, have been satisfied with the situation this season," team owner Rick Hendrick said. "We've put a ton of emphasis on the No. 5 program. It's been a total team effort, and Casey has worked as hard as anyone to help us improve. But the results just haven't come."

Mears, 30, joined Rick Hendrick's four-car team in 2007 as the driver of the No. 5 Chevrolet, replacing Brian Vickers.

"I know the effort has been there, but we haven't had the finishes to show for it," Mears said. "I've never tested this much or put more energy into racing. But for whatever reason, we just haven't been able to make it click. It's certainly not for lack of dedication on anyone's part."

Hendrick did not say who will drive the No. 5 Chevy next season, but ESPN.com reported Sunday that Mark Martin will join the team and take over for Mears full time in one final attempt to win a Cup title.

Mears had one victory and finished 15th in the Cup standings last year, but he has fallen to 24th this season and hasn't won a race. Mears believes he has other options available to him for 2009.

"I want to get my 2009 plans wrapped up soon," he said, "but I'm also focused on the next 20 races and finishing 2008 on a positive note. We ran well the second half last year and I know we can do it again. I want to close this season the right way."

Terry Blount covers motorsports for ESPN.com.