The lefty now appears geared for another doctor's visit for further examination to receive clearer answers about a stiff shoulder that put him on the 15-day disabled list on April 18.
"He had some discomfort throwing, and we will probably send him back to see [Lewis] Yocum," A's general manager Billy Beane said.
Braden initially paid a visit to Yocum, a noted orthopedic surgeon, in Los Angeles on April 20, when he was told he suffered no structural damage and wouldn't need to undergo a surgical procedure.
Rather, the hurler was encouraged to simply rest and rehab to calm inflammation in his shoulder. Braden has been doing just that, including range-of-motion exercises, and had noted gradual improvement, which led to Monday's unsuccessful session of catch.
Braden, 27, was 1-1 with a 3.00 ERA in three starts this season before the onset of his injury, yielding 18 hits while racking up 15 strikeouts and five walks.
It marks the third career DL stint for the southpaw, whose spot in the rotation has been temporarily filled by young right-hander Tyson Ross.