"They say his father was a fisherman"
Joe DiMaggio salutes his bat (1941)
Public DomainJoe DiMaggio salutes his bat (1941)
George Sisler at the University of Michigan, early 1900s
Public DomainGeorge Sisler at the University of Michigan, early 1900s
The old man and the boy are generally correct in their statements about DiMaggio's and Sisler's fathers. According to joedimaggio.com, “Giuseppe, [Joe’s] father, was a fisherman, as were generations of DiMaggio’s [sic] before him. He hoped all five of his sons would follow his footsteps. The two oldest sons, Tom and Michael, joined their father as fishermen but, Joe had no desire to follow in his father’s chosen career. As Joe recalled, he would do anything to get out of cleaning his father’s boat as the smell of dead fish made him sick to his stomach. This earned him Giuseppe’s ire, who called him ‘lazy’ and ‘good for nothing.’”

Dick Sisler's dad was "Gentleman George" (or sometimes "Gorgeous George") Sisler. He played professional baseball from 1915 to 1930. He was born in 1893, which means he started "playing in the big leagues" when he was about twenty-two. It seems unlikely that Manolin is that old.