beating out Alex Rodriguez to lead the team by a small margin. He was also one of only three players to hit a home run while pinch hitting in 2008, and the only one to do it twice. However, on November 4, 2008, the Yankees declined their option on Giambi for the 2009 season making him a free agent. Second stint with the Athletics (2009) On January 6, 2009, Giambi agreed to sign with the Oakland Athletics. He officially re-joined the A's the next day, and was given his old No. 16 jersey. Giambi hit his first home run since returning to the Athletics on April 25, 2009. On May 23, 2009, Giambi hit his 400th career home run in an 8–7 loss to the Arizona Diamondbacks. He was placed on the disabled list on July 20. At the time, Giambi had the lowest batting average in the majors, and fourth-lowest slugging percentage in the American League. On August 7, 2009, he was released by the A's. Colorado Rockies (2009–2012) Looking for a veteran bat to help their playoff push, the Colorado Rockies agreed to a deal with Giambi on August 23, 2009. He was assigned to their AAA affiliate, the Colorado Springs Sky Sox. Giambi chose to wear the number 23 for his jersey number. His first RBI with the Rockies came in the form of a bases loaded walk in his first plate appearance on September 1, 2009, after being promoted to the club upon roster expansion earlier that day. That year, he had many clutch hits which kept the Rockies in contention for the National League Wild Card. He quickly became a fan favorite in Colorado. On January 23, 2010, Giambi reached an agreement to return to the Rockies. On September 12, Giambi hit a walk-off home run against the Arizona Diamondbacks, extending the winning streak for the Rockies to 10 games. The Colorado Rockies announced on January 17, 2011, a deal to put Giambi in the team's minor league organization with a spring training invite for the 2011 season. Giambi made the 2011 Opening Day roster out of spring training. On May 19, 2011, against the Philadelphia Phillies, Giambi hit three home runs in one game, the first such game for him of his career. The three home runs came in his first three at-bats. Giambi is also the second oldest player to accomplish the feat;