Baseball

* Hitting coach Jeff Pentland was fired Monday by the struggling Kansas City Royals, who have lost six straight games and whose 13-37 record is the worst in the major leagues.

Kansas City's team batting average of .246 is the fourth-worst in baseball, and the Royals' on-base percentage of .309 is the second-worst in the majors.

Pentland, 58, was in his third season with the Royals. Kansas City named Andre David, its minor league hitting instructor the past five years, to replace him for the rest of the season.

The Royals, who had Monday off, open a series at home tonight against the New York Yankees. The team is in the process of looking for a permanent replacement for manager Tony Pena, who resigned May 10.

Kansas City is 5-12 under interim manager Bob Schaefer, who is among the candidates for the job.

* The Chicago White Sox extended the contract of manager Ozzie Guillen on Monday, making the move while the team had the best record in the majors.

The White Sox picked up the 2006 option on Guillen's contract, added two more years and included an option for the 2009 season.

In Guillen's second year as manager, the White Sox entered Monday's game against the Los Angeles Angels with a 33-17 record. They had been in first place in the AL Central from the first day of the season.

Guillen, 41, is the 37th manager in White Sox history and has a 116-96 record with the team.

* White Sox slugger Frank Thomas returned to the lineup on Monday for the first time since breaking a bone in his left ankle on July 6.

Thomas started as Chicago's designated hitter and batted third, as the White Sox opened a three-game series with the Los Angeles Angels. The White Sox opened a roster spot by optioning right-hander Brandon McCarthy to Triple-A Charlotte.

Thomas, who underwent offseason surgery Oct. 6 to repair a partial stress fracture in the ankle, hit just .190 in 11 games during a minor league rehabilitation assignment at Charlotte.