Eflin will have surgery on his left knee in the coming weeks, Todd Zolecki of MLB.com reports.
Eflin is currently recovering from last month's surgery on his right knee. He has had knee issues since he was a child and the Phillies are hopeful these two procedures will resolve those problems. GM Matt Klentak said the second surgery will likely happen during the first week of October. Eflin is expected to be ready for spring training.