Defending world champion in heptathlon Tatyana Chernova of Russia and two time world champion in high jump will miss Moscow world championships next month due to injuries they picked up this month.
Vlasic who won world titles in 2007 and 2007posted on her website that the pain in the old foot injury awoke after the diamond league meeting Monaco.
"The pain in my foot became more intense after the Diamond League competition in Monaco (on July 19) and it still has not calmed down as after the other competitions," said Vlasic.
"This is a clear sign that I need to stop for a while and recover completely. To jump in Moscow would be too much of a risk and could only jeopardize the future and I don't want to risk that."
Another high profile athlete, Tatyana Chernova, has also ruled out of Moscow's world championships after picking up an injury at Russian Outdoor championships last week. Chernova injured herself while running 100m hurdles individual race.