05/25/2003 12:00AM

Rider Warren to return Thursday


SAN MATEO, Ca. - Jockey Ron Warren Jr. took off his mounts at Bay Meadows on Sunday because of back spasms and will not ride again until Thursday.

Warren, second to Russell Baze in the jockey standings, will miss a chance to ride morning-line favorite Reba's Gold in Monday's $100,000 Grade 3 Seabiscuit Handicap at Bay Meadows.

Warren injured his back when pulling up favored High Counsellor on Friday night. He was excused from riding Saturday but tried to ride Sunday. After warming up his first mount, Midnight Charmer, Warren reported he was suffering from back spasms and was excused from his mounts for the rest of the day. He was X-rayed at an area hospital, but the X-rays were negative.