Canseco took nine pitches from Sasaki as part of a pregame ceremony at Yokohama Stadium. Canseco connected on a few pitches but none was a home run.
"His fastball and forkball haven't changed much since he was in the major leagues," Canseco said. "I should have practiced more."
Canseco, who hit 462 home runs in the major leagues, is in Japan to take part in a mixed martial arts event on Tuesday. The former Oakland A's slugger is fighting South Korean Hong Man Choi on the Dream 9 card in Yokohama Arena.
Choi is a 7-foot-2, 330-pound super heavyweight and has a 1-2 record in MMA.
Canseco, who named alleged steroid abusers such as himself in his two books, lost to former Philadelphia Eagle Vai Sikahema in his first foray into celebrity boxing.
He boxed Danny Bonaduce, a former "Partridge Family" child star, to a draw in a match in January.