World Athletics Championships 2019: Defending 100m champion Justin Gatlin suffers injury scare

The American picked up a thigh injury in Zagreb on Tuesday just three weeks before Doha

Justin Gatlin won silver at the World Championships in Doha (Getty)

World champion Justin Gatlin is a major doubt to defend his 100m title at the World Championships in Doha after picking up a thigh injury.

The American sprinter hurt his left thigh during an IAAF World Challenge meeting in Zagreb on Tuesday and must now recover inside three weeks.

Gatlin could only finish fourth in 10.29 seconds and could be seen in some anguish as he was assisted leaving the track.

The injury appeared to occur at around the 80m mark as Gatlin evidently felt discomfort.

The International Association of Athletics Federations confirmed the 37-year-old had sustained an injury, yet no further details are known on the severity at this stage.

Mike Rodgers is now a contender for Doha (AFP/Getty)

American Mike Rodgers won the race, clocking a time of 10.04 seconds.

Gatlin has run the fourth best time in the world this year with 9.87, but trails compatriot Christian Coleman, who is the fastest in 2019 at 9.81.

Coleman is now clear to race in Doha after seeing potential charges for three missed doping tests dropped.

The World Championships begin on September 27 with Gatlin required to be ready on the opening day for the 100m heats.