Chris Johnson is the sixth NFL player to rush for more than 2,000 yards.

But how would the 2009 NFL rushing champion fare on a running track, without a helmet and pads, against Usain Bolt, the world's fastest man?

We might never know.

The Tennessee Titans running back said Monday as he cleaned out his locker that he recently learned that a potential race against the Jamaican Olympian isn't going to happen -- at least, not at a distance less than 100 meters, where Bolt holds the world record.

"We got word two days ago. He don't want to do it. He only wants to run the 100, he don't want to run the 50," Johnson said. "He said the only way he'll do it is if he runs the 100."

ESPN NFL Insider Adam Schefter reported Monday that according to sources, representatives for the Titans running back and Bolt had spent recent days trying to set up a race between the two men to determine who really is the world's fastest human.

According to sources, the hangup seemed to be the length of the race. Johnson wanted the race to be 60 yards or less, while Bolt wanted it to be longer.

The race would be used to raise money for charity.

But Bolt's agent, Ricky Simms, told Universal Sports.com that it the race was not going to happen.

"Usain doesn't follow the NFL too closely and is not really familiar with all of the players. He likes [international] football and cricket," Simms said, according to the report. "But more importantly, he has a schedule and a coach to follow and there is no chance that we would set up this type of event."

Bolt won three gold medals at the 2008 Summer Olympics in Beijing, setting world records in the 100 meters and 200 meters and sharing a third world record with the Jamaican 4x100 meter relay team. At last year's world championships, he shattered both of his own sprinting world records, running the 100 meters in 9.58 seconds and the 200 meters in 19.19 seconds.

Johnson on Sunday became the NFL's sixth 2,000-yard rusher when he completed his season with 2,006, breaking Earl Campbell's franchise record of 1,934. The second-year back from East Carolina also broke Marshall Faulk's NFL single-season record with 2,254 total yards from scrimmage.

At the 2008 NFL scouting combine, Johnson was timed in the 40-yard dash at 4.24 seconds -- the fastest time clocked at the combine that year.

Johnson's longest run from scrimmage this season was a 91-yard touchdown run in Week 2.

ESPN.com's Paul Kuharsky and ESPN NFL Insider Adam Schefter contributed to this report.