In December 2008, several members of the Boston Red Sox organization, including pitching coach John Farrell, vice president of player personnel Ben Cherington and assistant trainer Mike Reinold, flew to Atlanta to participate in a 90-minute workout with Smoltz.
Throwing for only the second time since having surgery on a torn labrum in his pitching shoulder, he threw a 50-pitch side session and showcased not only his tremendous progress since the surgery, but an arsenal of well-developed pitches which made him so successful throughout his career.
He impressed the Red Sox enough during the workout that less than a month later, a one-year contract was offered by the organization.

On January 13, 2009, Smoltz signed a one-year contract with the Red Sox for a reported base salary of $5.5 million with roster time incentives and miscellaneous award incentives which could net as much as $10 million.
He made his first start in the Red Sox rotation on June 25, allowing seven hits and five runs through five innings.
Smoltz posted a 2–5 record over eight games with an 8.32 ERA and no quality starts.
He was designated for assignment on August 7 after a 13–6 loss to the New York Yankees, giving the Red Sox ten days to release or trade him, or send him to the minors.
The Red Sox offered Smoltz a minor league stint in order to prepare him to be placed in the bullpen, but he rejected the offer.
On August 17, the Red Sox released Smoltz.
In December 2008, several members of the Boston Red Sox organization, including pitching coach John Farrell, vice president of player personnel Ben Cherington and assistant trainer Mike Reinold, flew to Atlanta to participate in a 90-minute workout with Smoltz. Throwing for only the second time since having surgery on a torn labrum in his pitching shoulder, he threw a 50-pitch side session and showcased not only his tremendous progress since the surgery, but an arsenal of well-developed pitches which made him so successful throughout his career. He impressed the Red Sox enough during the workout that less than a month later, a one-year contract was offered by the organization.
On January 13, 2009, Smoltz signed a one-year contract with the Red Sox for a reported base salary of $5.5 million with roster time incentives and miscellaneous award incentives which could net as much as $10 million. He made his first start in the Red Sox rotation on June 25, allowing seven hits and five runs through five innings. Smoltz posted a 2–5 record over eight games with an 8.32 ERA and no quality starts. He was designated for assignment on August 7 after a 13–6 loss to the New York Yankees, giving the Red Sox ten days to release or trade him, or send him to the minors. The Red Sox offered Smoltz a minor league stint in order to prepare him to be placed in the bullpen, but he rejected the offer. On August 17, the Red Sox released Smoltz.
John Smoltz