Apprentice jockeys William Cox and Eoin Walsh were taken to hospital following a three-horse pile-up at Wolverhampton.
The riders went to the local New Cross Hospital after the incident, which occurred on the turn for home about two furlongs from the finish in the sunbets.co.uk Download The App Apprentice Handicap.
Cox was aboard the John Flint-trained Mobley Chaos, who brought down Secret Lightning, ridden by Walsh.Binky Blue also came down, but his rider Toby Eley appeared to escape relatively unscathed.
"Two of the three jockeys have been referred on to New Cross Hospital for further investigation and checks," said clerk of the course Fergus Cameron."They are William Cox and Eoin Walsh. Toby Eley walked back."
The three horses involved were reported to have returned safely, but racing was delayed until medical cover was restored to the track.
The seven-furlong heat was won by the Jo Hughes-trained Wink Oliver, ridden by Laura Coughlan.