Chamberlain learned about his role in the Yankees rotation in November, and stated that knowing about the team's plans to use him as a starter rather than as a reliever who would move into a starting role at some point in the middle of the season (as was the case in 2008) changes his mental approach to preparing for the season, and makes things easier on him.
 During the All-Star break, Chamberlain went back home to Lincoln, Nebraska to get his mind off things by playing with his son so he could "be himself" and get more confidence on the mound.
 Chamberlain continued to struggle in the second half of the season.
The Yankees considered demoting him to the minor leagues and leaving him off of the postseason roster, but the Yankees kept Chamberlain on the roster in a set-up role as the Yankees went with a three-man starting rotation en route to winning the 2009 World Series.

Heading into the new season, before spring training Yankees manager Joe Girardi declared that there would be competition for the fifth spot in the Yankees starting rotation.
The favorites were most notably Chamberlain and Phil Hughes.
Towards the end of spring training, Hughes was declared the winner, which sent Chamberlain back to the bullpen.
From the start of the season through July Chamberlain struggled, with an ERA over 5.
His performance improved in August and September; in Chamberlain's last 28 appearances of the 2010 regular season, his ERA was 2.38.

The Yankees ruled out using Chamberlain as a starting pitcher in 2011 arguing that his pitches have greater velocity when he pitches in relief.
 At the beginning of the season, he was moved to the seventh-inning role to accommodate Rafael Soriano.
He would later become the set-up man to Mariano Rivera briefly after Soriano went on the disabled list.
Chamberlain was placed on the 15 day-disabled list on June 8 due to an elbow injury.
He had Tommy John surgery performed on June 16 to repair a torn ligament in his right elbow and was knocked out for the rest of the season.

In January 2012, the Yankees and Chamberlain agreed on a one-year, non-guaranteed contract worth approximately $1.675 million.
On March 22, 2012, Chamberlain injured his right leg while bouncing on a trampoline in a Tampa jump center; he suffered an open dislocation of his ankle.
 Initial reports indicated that he had lost so much blood that onlookers at the scene feared that he might bleed to death.
Chamberlain, however, later discredited these accusations during a press conference stating that he never suffered any life-threatening injury nor did he lose much blood.
Chamberlain began the 2012 season on the 60-day disabled list due to the ankle injury, and he was recovering from the Tommy John surgery he had previously.
He returned on August 1, 2012, against the Baltimore Orioles.

In the top of the 12th inning of Game 4 of the 2012 American League Division Series, Chamberlain was struck on the elbow by a broken bat by Matt Wieters of the Orioles and left the game.
Despite his injury, the Yankees won the series over Baltimore in five games, but were swept in the 2012 American League Championship Series by the Detroit Tigers.

On May 2, 2013, Chamberlain was placed on the 15-day disabled list with a right oblique strain.
He was activated from the DL on May 28, 2013.

On September 5, 2013, Chamberlain was ejected for the second time in his major league career in a 9–8 Yankees loss against the Red Sox.
With Jacoby Ellsbury on second after a stolen base and Shane Victorino at the plate with one out in the 10th inning, Victorino attempted to check his swing on a 1-2 pitch and first base umpire Joe West said Victorino did not swing, Victorino then singled in the go-ahead run on the very next pitch, Chamberlain was then ejected by West for arguing the check swing call after being removed from the game.
Chamberlain learned about his role in the Yankees rotation in November, and stated that knowing about the team's plans to use him as a starter rather than as a reliever who would move into a starting role at some point in the middle of the season (as was the case in 2008) changes his mental approach to preparing for the season, and makes things easier on him.  During the All-Star break, Chamberlain went back home to Lincoln, Nebraska to get his mind off things by playing with his son so he could "be himself" and get more confidence on the mound.  Chamberlain continued to struggle in the second half of the season. The Yankees considered demoting him to the minor leagues and leaving him off of the postseason roster, but the Yankees kept Chamberlain on the roster in a set-up role as the Yankees went with a three-man starting rotation en route to winning the 2009 World Series.
Heading into the new season, before spring training Yankees manager Joe Girardi declared that there would be competition for the fifth spot in the Yankees starting rotation. The favorites were most notably Chamberlain and Phil Hughes. Towards the end of spring training, Hughes was declared the winner, which sent Chamberlain back to the bullpen. From the start of the season through July Chamberlain struggled, with an ERA over 5. His performance improved in August and September; in Chamberlain's last 28 appearances of the 2010 regular season, his ERA was 2.38.
The Yankees ruled out using Chamberlain as a starting pitcher in 2011 arguing that his pitches have greater velocity when he pitches in relief.  At the beginning of the season, he was moved to the seventh-inning role to accommodate Rafael Soriano. He would later become the set-up man to Mariano Rivera briefly after Soriano went on the disabled list. Chamberlain was placed on the 15 day-disabled list on June 8 due to an elbow injury. He had Tommy John surgery performed on June 16 to repair a torn ligament in his right elbow and was knocked out for the rest of the season.
In January 2012, the Yankees and Chamberlain agreed on a one-year, non-guaranteed contract worth approximately $1.675 million. On March 22, 2012, Chamberlain injured his right leg while bouncing on a trampoline in a Tampa jump center; he suffered an open dislocation of his ankle.  Initial reports indicated that he had lost so much blood that onlookers at the scene feared that he might bleed to death. Chamberlain, however, later discredited these accusations during a press conference stating that he never suffered any life-threatening injury nor did he lose much blood. Chamberlain began the 2012 season on the 60-day disabled list due to the ankle injury, and he was recovering from the Tommy John surgery he had previously. He returned on August 1, 2012, against the Baltimore Orioles.
In the top of the 12th inning of Game 4 of the 2012 American League Division Series, Chamberlain was struck on the elbow by a broken bat by Matt Wieters of the Orioles and left the game. Despite his injury, the Yankees won the series over Baltimore in five games, but were swept in the 2012 American League Championship Series by the Detroit Tigers.
On May 2, 2013, Chamberlain was placed on the 15-day disabled list with a right oblique strain. He was activated from the DL on May 28, 2013.
On September 5, 2013, Chamberlain was ejected for the second time in his major league career in a 9–8 Yankees loss against the Red Sox. With Jacoby Ellsbury on second after a stolen base and Shane Victorino at the plate with one out in the 10th inning, Victorino attempted to check his swing on a 1-2 pitch and first base umpire Joe West said Victorino did not swing, Victorino then singled in the go-ahead run on the very next pitch, Chamberlain was then ejected by West for arguing the check swing call after being removed from the game.
Joba Chamberlain