The Diamond League meeting in Eugene will not see its top star athlete, David Rudisha, since he was forced to withdraw from the event due to knee injury he suffered this week.
On Wednesday in Eugene, the MRI was performed on Rudisha's knee showing bruised bone and underlying ligaments. Athlete then tried to do a light practice on Thursday, but it did not go as planned.
The latest additions to the meeting are two Americans, Sanya Richards-Ross in the women's 400m and Walter Dix in the men's 200m race.
Great Britain's double Olympic champion Mo Farah switched from racing 10,000m to 5,000m due to stomach virus.
“It was a day of turmoil,” said Eugene Diamond League meet director Tom Jordan.
The Prefontaine Classic starts on Friday, May 31 at 6:00pm with a "Distance Night in Eugene" and will continue on Saturday, June 1 at 3:00Pm with the main Diamond League portion.