The White Sox simply haven't been able to get any power production from a left-handed hitter since Jim Thome began declining and eventually left. But that's about to change.

Sports Illustrated's Jon Heyman reports that Chicago has agreed to a four-yeal, $56 million deal with slugging first baseman Adam Dunn. The Los Angeles Times reported the White Sox were closing in on a deal earlier on Thursday, as Chicago had had ongoing negotiations with Dunn throughout the week.

Dunn hit .260/.358/.536 with 38 home runs and 103 RBIs for the Nationals in 2010. He's hit at least 38 homers in each of the last eight seasons, and hit at least 40 bombs from 2004 to 2008.

The 31-year-old could DH for the White Sox, or play first base if the team does not decide to bring back Paul Konerko, who had a monster 2010 season but is 34 years old and is seeking a multi-year deal.