CINCINNATI - Ken Griffey Jr. is back in a pennant race. The Chicago White Sox acquired Griffey from his hometown Cincinnati Reds on Thursday, hoping the 38-year-old outfielder can help them hold onto their slim lead in the AL Central.

Cincinnati Reds' Ken Griffey Jr. trots home after New York Mets starter John Maine (33) hit Edwin Encarnacion with a pitch with the bases loaded in the fourth inning of a baseball game, Friday, July 18, 2008, in Cincinnati. (AP Photo/Al Behrman)

The Reds sent Griffey and cash to Chicago for reliever Nick Masset and Triple-A second baseman Danny Richar.

The deal was announced a half-hour before the 4 p.m. EDT deadline to make trades without waivers.

Griffey, who hit his 600th home run this season, agreed to the trade earlier in the day. But because of the cash transaction involved, the deal did not become official until the commissioner's office approved it.

White Sox general manager Kenny Williams had coveted Griffey for several years. Now older, it's uncertain how much Griffey has left and where he will fit in with Chicago. The White Sox began the day with a 1 1/2-game division lead over Minnesota.

Once one of baseball's premier players, the oft-injured Griffey has never reached the World Series and has not even been in the playoffs since 1997 with Seattle.

Griffey became the sixth player to reach 600 career homers this season, but has struggled at the plate. He's batting .245 with 15 homers and 53 RBIs despite playing in one of the most homer-friendly ballparks in Cincinnati.

Griffey joined the Reds before the 2000 season, agreeing to a nine-year, $116.5 million deal. He makes $12.5 million this season, and there's an option for 2009 at a $16.5 million salary. If a team doesn't want to pick up next year's option, Griffey will be owed a $4 million buyout under his contract.

The Reds were interested in dealing Griffey because of the size of his contract and their plummet after the All-Star break, which dropped them back to near the bottom of the NL Central, 13 1/2 games out of first place. The Reds haven't had a winning season since 2000.

Griffey could play center field for Chicago, with Nick Swisher moving to first base in place of slumping Paul Konerko. After Chicago lost to Minnesota 6-5 on Tuesday night, manager Ozzie Guillen indicated he was considering shifting Swisher to first base, but he wasn't confident anyone could take his place in center.

Swisher and Konerko could split the job at first, or Konerko and Jim Thome could platoon as the designated hitter. The White Sox are set in left and right field with Carlos Quentin and Jermaine Dye.

Griffey was an All-Century center fielder with Seattle, but his speed has diminished in the last few years because of age and injury. The Reds moved him to right field before the 2007 season, a switch that the outfielder initially disliked. Rookie Jay Bruce currently plays center for Cincinnati.

The trade that united Griffey with his hometown team in 2000 was hailed as a major breakthrough for the franchise, but turned out to be far less than expected. After the 2002 season, former general manager Jim Bowden tried to trade Griffey to San Diego for Phil Nevin, who used his no-trade clause to block the deal.

Bowden was trying to work out a deal with the Yankees in 2003 before Griffey got hurt. The White Sox also have shown an interest in Griffey, but Reds ownership was reluctant to trade its most prominent player as he closed in on 600 homers.

Masset, a righty, was 1-0 with a 4.63 ERA in 32 games for Chicago. Richar hit .262 with nine homers for Triple-A Charlotte.