"We'd be concerned if any player was carrying an injury that may affect his participation in the Ashes series and we'll look at that as we move forward," said Collier.
The ECB has allowed Flintoff, Kevin Pietersen and Paul Collingwood to play for a maximum three weeks of the six-week IPL season, while Ravi Bopara and Owais Shah have also been signed up to play in India.
Australia captain Ricky Ponting and batsman Michael Clarke have already pulled out of this year's IPL to concentrate on their side's congested national team calendar.
Asked if the ECB could stop Flintoff playing, Collier said: "There are medical clauses.
"The IPL are very responsible in that area and we have very, very strong relationships with Chennai. Andrew's own team will also be looking at the injury prognosis."
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