Apprentice rider Michael Straight possibly has been left paralyzed in his lower body after being seriously injured when his mount fell in the eighth and final race Wednesday at Arlington Park.\nA friend who was with Straight and his family until late in the night at Luther General Hospital in Park Ridge, Ill., said doctors treating the 24-year-old rider informed them that Straight had sustained four fractured vertebrae. The friend, speaking on condition of anonymity, said family and friends were told to "pray for the best but prepare for the worst" and that the prognosis for Straight being able to walk again was "very grim."\nIt was initially feared that Straight might have suffered major head or brain trauma, but by Thursday morning, doctors were optimistic that was not the case, according to the friend. Straight was scheduled to undergo surgery and further evaluation of his spinal condition Thursday. The initial prognosis was that Straight would continue to have use of his upper body.\nStraight was injured in the 1 1/16-mile Polytrack race when his mount, Im No Gentleman, fell suddenly when appearing to clip the heels of Conte Ridge nearing the quarter pole. Im No Gentleman, a 3-year-old gelding bred and owned by Jay Collier and trained by Clayton Pierce, was racing near the back of the pack of $10,000 maidens when the spill occurred. Im No Gentleman died as a result of the accident. There were no other horses or jockeys seriously injured.\nStraight graduated last year from the North American Riding Academy, the school founded and operated in Lexington, Ky., by retired Hall of Fame jockey Chris McCarron. He is the identical twin brother of jockey Matthew Straight, who graduated from the McCarron riding academy one year earlier and has been riding lately at Ellis Park in Kentucky.\nOn behalf of his family, Matthew Straight issued the following statement early Thursday afternoon through the Arlington media-relations department: "As of noon [Central] today, Mike is stable and is scheduled to undergo surgery later this afternoon. The surgery is expected to last several hours. We will issue a further update Friday morning."\nArlington spokesman Dave Zenner and Straight's agent, Michelle Barsotti, both declined comment, citing privacy issues and deference to Straight's family.\nThe Straight brothers grew up in East Greenbush, N.Y., and became interested in the sport by attending the races at nearby Saratoga. Michael Straight won with the first mount of his career on March 6 at Tampa Bay Downs. In all, he has ridden 39 winners from 372 mounts, with 23 of his wins coming at Arlington.\nArlington chairman Richard Duchossois arranged for a charter jet to fly the twins' parents to be with Michael on Wednesday night. Matthew was driven by a friend from Kentucky to be with his brother.\nThe spill was the second at the Arlington meet that resulted in severe injury. Rene Douglas suffered a major spinal injury in a May 23 race and continues to recuperate in the Chicago area.\nMeanwhile, the start of the Thursday card at Arlington was delayed by 30 minutes after a meeting between jockeys, horsemen, and Arlington management went long. According to one anonymous source who was in attendance, among the numerous issues discussed were conditions of the Polytrack surface, which has not met to the satisfaction of some trainers or jockeys.