The Colts gave Locke, who had spent the previous four seasons with the Minnesota Vikings, a two-year, $3.45 million contract with $1.25 million guaranteed in March after McAfee unexpectedly announced his retirement last winter.
Locke averaged 43.5 yards on 11 punts in the preseason. He was new Colts general manager Chris Ballard's first unrestricted free agent signing on March 10.
Locke's release means undrafted rookie free agent Rigoberto Sanchez has the inside track to be the Colts' punter and kickoff specialist. Sanchez is averaging 47.2 yards on punts in the preseason.
The Colts also traded long snapper Thomas Hennessy to the New York Jets for safety Ronald Martin on Monday. Martin played 11 games during the 2015-16 seasons with the Jets while also spending some time on their practice squad.