The Boston Red Sox activated infielder Kelly Johnson from the disabled list ahead of Thursday night's game against the St. Louis Cardinals.

Johnson, 32, was acquired from the New York Yankees in exchange for Stephen Drew despite Johnson being on the disabled list with a groin injury. He has been out since July 22.

To make room for Johnson, rookie outfielder Mookie Betts was demoted to Triple-A Pawtucket.

Betts, a 21-year-old top prospect, had started just two of his last five games as the team struggled to find playing time for him. He is hitting .244 in 41 at-bats on the season.