Atlanta placed Lee on the paternity list Tuesday.
Lee has been an effective high-leverage relief option for Atlanta early in the season with a 1.38 ERA, 0.62 WHIP and 13:2 K:BB over 13 innings, but he will step away from the team for a few days in order to be with his growing family. He should be back with the club for Friday's series opener in Colorado. Didier Fuentes was called up Tuesday in a corresponding move.