Merritt was called up from Triple-A on Monday, Ryan Lewis of the Akron Beacon Journal reports.
Merritt will take Joba Chamberlain's place while he is on the 15-day DL with a rib injury. The 24-year-old has been successful at the Triple-A level this year, posting a 2.94 ERA in eight starts, and will look to keep it going at the big league level in what will likely be a short stint with the Indians.