When agent Tony Attanasio heard 32-year-old Japanese righthander Kazuhiro Sasaki was looking for an agent to get him to the majors, he called Mets skipper Bobby Valentine, who once managed against him in Japan. Said Valentine, "If Mariano Rivera was available, would you get on the next plane? He's that good." Attanasio jetted to Japan and got his man. Now the Mariners, by shelling out $9.5 million over two years, have him. Sasaki, who throws a devastating split-fingered fastball, will be used at first as a setup man, but he has no intention of being No. 2 to Jose Mesa in the bullpen. "I want to close," says Sasaki. "That's what I am used to."