The right-hander agreed to an $82.5 million, five-year contract with Boston in December 2009 that contained a provision for a conditional team option at the minimum if he missed a season due to specified injury. Lackey did not pitch in 2012 after reconstructive elbow surgery.
The major league minimum next year will be $500,000 plus a cost-of-living adjustment to be determined Nov. 20, which is likely to be $9,000 to $10,000.
Lackey, who turned 36 on Oct. 23, was 14-10 with a 3.83 ERA last year with the Red Sox and Cardinals and was 1-0 in two postseason starts for the NL Central champions.
He was acquired at the trade deadline in July in a deal that sent outfielder Allen Craig and pitcher Joe Kelly to Boston. Cardinals general manager John Mozeliak said the contract option was a key to the deal.