The move allows Smoltz to sign with any other team. And according to ESPN The Magazine's Buster Olney and ESPN.com's Jayson Stark, there appear to be several suitors in the Los Angeles Dodgers, Florida Marlins, St. Louis Cardinals and Texas Rangers.
Whatever team decides to acquire Smoltz would be on the hook for the pro-rated amount of the major league minimum. In addition, Smoltz would get the rest of his $5.5 million salary from the Red Sox.
The 42-year-old right-hander signed with the Red Sox last January after two decades with Atlanta, where he was a Cy Young Award winner and eight-time All-Star. Smoltz was particularly memorable in the postseason, going 15-4 with four saves and 2.65 ERA.
That record prompted Boston to sign take a chance and sign him to a one-year contract, knowing he couldn't pitch immediately as he recovered from right shoulder surgery.
He never really made it back.
After eight starts with the Red Sox, Smoltz was 2-5 with an 8.32 ERA. General manager Theo Epstein flew to New York on Aug. 7 to give Smoltz the word in person that he was being designated for assignment. The team had until Monday to trade, release or send him to the minors.
Tom Glavine said he had not talked with his former Braves teammate, but he predicted Smoltz will pitch again.
"I'm sure someone will grab him," Glavine said in a text message to The Associated Press.
There is no room for Smoltz to make a return to Atlanta, general manager Frank Wren said Monday.
"With the anticipated addition of Tim Hudson in the near future we have not pursued John Smoltz," Wren said in an e-mail on Monday.
The Braves are preparing to add Hudson to a staff that already includes starters Derek Lowe, Javier Vazquez, Jair Jurrjens, Kenshin Kawakami and Tommy Hanson. Hudson, returning from elbow surgery, is in an injury rehab assignment with Triple-A Gwinnett.
In his final appearance with the Red Sox, the Yankees battered Smoltz for eight runs on nine hits and four walks in 3 1/3 innings.
"I'm not doing it right now," Smoltz said then. "I'm a big enough man to stand up here and say I'm not doing it."
Smoltz -- who was 212-152 with 154 saves and a 3.32 ERA since his major league debut in 1988 -- has called being cut by the Red Sox "humbling."
Smoltz helped Atlanta to its single World Series championship and is the only pitcher with more than 200 victories and 150 saves.
"Time may not be on my side if this continues," he said.
His agent, Lonnie Cooper, did not immediately respond to an e-mail seeking comment Monday.
Information from The Associated Press contributed to this report.