Derby Entrant King Guillermo Misses Training Sept. 3

The status of King Guillermo for the Sept. 5 Kentucky Derby Presented by Woodford Reserve (G1) is up in the air after the grade 2 winner skipped a scheduled trip Sept. 3 to the Churchill Downs track.

Trainer Juan Carlos Avila said the horse has a "little problem" and they'll have to wait until this afternoon or evening to make a final call. Avila declined to elaborate other than to say there would be a meeting with the horse's veterinarian and there may be further information around 6 p.m. ET.

"It's a big race and a little problem is a big problem for me," Avila said of the timing of the issue two days before the Derby.

King Guillermo has not raced since finishing second to Nadal in a division of the Arkansas Derby (G1) May 2 at Oaklawn Park. Before that effort, the son of Uncle Mo  delivered an upset victory in the Lambholm South Tampa Bay Derby (G2). He has been training at Churchill Downs for more than a month after traveling from his regular base in Florida.

The colt is owned by retired Major League Baseball All-Star Victor Martinez, who races under the stable name Victoria's Ranch.

Martinez declined to comment Thursday morning, saying he was with his family and talking to his trainer. He said he would speak to reporters later.

The stewards said they had not received any scratches for the Derby, as of 10:30 a.m. Thursday. Early scratches are not due until 9:00 a.m. Sept. 4, though horses can still be withdrawn after that time.

This story will be updated.