In 2010, Affeldt again spent the entire season in the bullpen for the Giants. On March 28, the Giants extended his contract through the 2011 season with an option for 2012. Affeldt picked up his first save with the Giants in a 6–3 victory over the Atlanta Braves on April 11. He struggled for most of the season and was placed on the disabled list on July 24 with an oblique strain. After rehabbing in the minors, Affeldt returned to the Giants on August 18. He finished the season with four saves and a 4.14 ERA in fifty–three games.