Dixon, the former Oregon star, has spent most of the season as the No. 3 quarterback running the scout team for the Steelers (6-4) during practice. He has thrown only one NFL pass in two seasons, but must play because both Roethlisberger and backup Charlie Batch were hurt during a 27-24 overtime loss to Kansas City last week.

The Steelers said yesterday that Roethlisberger would play only in an emergency. He will be the No. 3 quarterback, with former Pitt starter Tyler Palko - who was signed Thursday - as Dixon's backup.

Roethlisberger practiced all week despite his fourth concussion since 2006.

He experienced headaches, however, resulting from the concussion - he struck the knee of Chiefs linebacker Derrick Johnson as he leaned headfirst during a running play - and he decided against playing after consulting with the team's medical staff.

Jerry Rice and Emmitt Smith are among 25 semifinalists for the Pro Football Hall of Fame.

Former Raiders receiver Tim Brown and Cardinals and Rams defensive back Aeneas Williams were the only other players selected in their first year of eligibility.

The semifinalists include a coach, Don Coryell, and two contributors, Art Modell and former commissioner Paul Tagliabue. Former Eagles Cris Carter and Richard Dent are also on the list.

Dick LeBeau and Floyd Little already had been selected as finalists by the Seniors Committee.

Indianapolis Colts defensive end Dwight Freeney will miss today's game against the Houston Texans because of an abdominal injury.

Indy (10-0) can clinch the AFC South title with a win and a Jacksonville loss.

BASEBALL: Commissioner Bud Selig, 75, plans to step down at the end of his contract after the 2012 season, the Chicago Tribune reported.

Selig told a group of five owners asking him to stay on that he intends to pursue other interests.

GOLF: Graeme McDowell and Rory McIlroy shot an 8-under-par 64 in fourball, but Ireland's lead over defending champion Sweden and Italy shrank from 3 strokes to 1 at 26-under 190 in the World Cup of Golf in China.

Sweden's Robert Karlsson and Henrik Stenson had a 10-under 62, and the Italian brothers Edoardo and Francesco Molinari shot an 11-under 61 to slice Ireland's lead at Mission Hills Golf Club in the southern Chinese city of Dongguan.

TENNIS: Top-ranked Roger Federer was eliminated from the ATP World Tour Finals, losing to Nikolay Davydenko, 6-2, 4-6, 7-5, in the semifinals.

Davydenko will meet U.S. Open champion Juan Martin del Potro in today's final. Del Potro defeated Robin Soderling, 6-7 (1), 6-3, 7-6 (3).

COLLEGES: A Louisiana State official said Tigers assistant Larry Porter accepted an offer to become the next head football coach at Memphis.

HORSE RACING: Super Saver set a stakes record in winning the $191,250 Kentucky Jockey Club Stakes for 2-year-olds at Churchill Downs.

Ridden by Calvin Borel for trainer Todd Pletcher, Super Saver ran the 11/16 miles in 1 minute, 42.83 seconds to eclipse the stakes record of 1:43.14 set by Captain Steve in 1999.

Lentenor, a full brother to the late Barbaro, was second in a maiden race for 2-year-olds at Aqueduct.