Former American 400m runner Michael Johnson has admitted that he was concerned by the performance of Great Britain's Christine Ohuruogu earlier today.
Despite leading her heat in the closing stages, Ohuruogu decided to ease up, which allowed Francesca McCorory to win the race.
That decision is something that Johnson believes could cost the defending champion a positive lane draw in the semi-finals tomorrow.
"The first 350m, fine. But the last 50m is what worries me about Christine," he told BBC Sport. "She was very much in control of the race and very relaxed for the first 200m. But she just shut down far too early.
"You don't want to do that because you want a good lane draw the next day."
Ohuruogu, 28, will learn which lane she will compete in later today.
