Lambo was called up from Triple-A Nashville on Monday and then placed on the 60-day DL.
Lambo is undergoing treatment for testicular cancer and remains without a timetable to return to baseball activities, so the Athletics will be able to open up a 40-man spot by stashing him on the 60-day DL. The 27-year-old's long-term health remains a greater priority than his baseball career at this point, so the Athletics are content to give him as much time away from the game as he needs.