But Sweeney came back to the field, and Portland, in the midseason of 1956 for a third and final stint as skipper of the Beavers. He succeeded Tommy Holmes as manager and led the Beavers to a third-place finish and was invited to return for 1957. However, on April 18, only six games into the 1957 campaign, Sweeney was stricken with a perforated ulcer in San Diego, where his club was playing. He survived emergency surgery but then died from a heart attack at the age of 52. He was interred in Resurrection Cemetery, San Gabriel, California.