Merryweather will undergo surgery on his right knee Friday, Mike McGraw of the Chicago Daily Herald reports.
Merryweather has been on a rehab assignment at Triple-A Iowa since last Friday, during which he's thrown two scoreless innings while striking out three batters and walking one. However, his attempt at a return this season will be put to an abrupt end, as he's elected to undergo surgery to address the tendinitis in his knee. A recovery timeline will likely emerge after the 32-year-old goes under the knife.