In what is likely their final attempt to bolster their roster for the postseason, the Oakland Athletics have acquired designated hitter Adam Dunn from the Chicago White Sox on Sunday.

Dunn was involved in some trade discussions prior to the deadline, but he remained in Chicago where he's been for the past four seasons. He'll now join one of the best teams in baseball and likely participate in the playoffs for the first time in his career after failing to reach the postseason in seven seasons with the Cincinnati Reds, one with the Arizona Diamondbacks, two with the Washington Nationals, and three-plus with the White Sox.

The Athletics have been atop the MLB standings all season, but the Los Angeles Angels have dominated the league since the All-Star break and snagged the division lead from Oakland. They now lead by five games with their 83-53 record while the A's sit in second place with the third-best record in baseball (78-58). This will be the third significant trade the team has made in an effort to break away from the pack and ensure a deep playoff run.

Oakland first traded for pitchers Jeff Samardzija and Jason Hammel with the Chicago Cubs in early July and then acquired All-Star Jon Lester from the Boston Red Sox on the day of the trade deadline. Now with the acquisition of Dunn, the team hopes he'll fill the void left by Yoenis Cespedes, who was sent to Boston for Lester. Dunn, nicknamed the Big Donkey, has hit at least 20 home runs in 12 of his last 13 seasons, including four 40-home-run seasons in a row from 2005-2008.

Today was the last day that the Athletics or any other team in the MLB could have acquired another player via a waiver trade in order for them to be eligible for the postseason roster. Oakland will pay half of Dunn's remaining $2.5 million salary and also receive unspecified cash considerations while the White Sox were given minor league relief pitcher Nolan Sanburn (3.28 ERA with six saves in 42 appearances with Class-A Stockton).

With under a month remaining in the season, the Athletics hope Dunn will help contribute to their lineup that leads the majors in runs scored as the team looks to win the AL West division title.