ATLANTA (AP) _ Michael Johnson is human after all.

The first man to win the Olympic 200 and 400 said Friday that he won't run in the 1,600-meter relay because of a hamstring injury.

Johnson said he felt tightness in the lower right hamstring at the end of Thursday's 200-meter finals, when he set a stunning world record of 19.32 seconds. He felt a twinge five meters from the tape.

``It's not a pull, there's no damage, just a little swelling,'' Johnson said.

The 200 final was Johnson's eighth race in seven days _ all run in hot, steamy weather on the extremely hard Olympic Stadium track. Before taking a victory lap, he secured an ice bag to the back of his leg.

Even without Johnson, the U.S. 1,600-meter relay team has a strong chance to win the gold.

On Friday morning, Anthuan Maybank, Derek Mills, LaMont Smith and Jason Rouser won their heat in 3:00.56 _ the fastest time of the first round and one of the world's fastest times this year.

``There are a lot of guys capable of running, and I don't want to hurt the chances for a gold medal,'' Johnson said. ``There are a lot of others who are capable.''

In the semifinals Friday night, Smith, Jason Rouser, Mills and Maybank went even faster, finishing in 2:57.87.

Johnson had planned to sit out the first rounds before anchoring the finals Saturday.

Butch Reynolds, who holds the 400-meter world record at 43.29, also is on the relay team, but he was felled during a 400 qualifying race with hamstring cramps. He says he will run in the finals.

Johnson has managed to live up to tremendous expectations during these games, setting an Olympic record of 44.49 while winning the 400, then obliterating his own 200 world record by the largest margin ever in that event.

It has been sweet vindication from the 1992 Barcelona Olympics, when Johnson concentrated on the 200 but failed to get past the semifinals because he was sick with food poisoning.

Still weak, Johnson was nonetheless put on the 1,600 relay. The U.S. team, which also included Andrew Valmon, Quincy Watts and Steve Lewis, proceeded to set a world record of 2:55.74.

Johnson said his goal had been to leave Atlanta with three gold medals.

``I'm disappointed I can't run in the 4x400, but I guess you can't get everything,'' he said. ``I'm confident the four guys who go out will bring the gold.''