Any American male is a liar if he denies dreaming of hitting a game-winning, bases-loaded home run in the last in the ninth of the World Series.

Chances of realizing that fantasy have been just about zero for legendary baseball stars from Babe Ruth to Jose Canseco.But odds improve considerably for Hollywood actors.

One actor who dreamed just such a dream is Tom Selleck, one of the best actor-athletes in recent memory. In "Mr. Baseball," the tall, ruggedly built Selleck has the opportunity to hit all kinds of homers in the role of an American baseball star in Japan.

Long a baseball fan - particularly of the Detroit Tigers - Selleck also was a basketball and volleyball flash during his high school and college days. Through the years he has stayed trim and muscular working out on court and diamond.

The other day Selleck's face was wreathed in a huge grin when he said, "I've always wanted to do a baseball picture. I still play baseball pretty well.

"The game has been a great love of mine and I really believe that a good baseball film can serve as a metaphor for life better than almost any other sport."

The most enjoyable part for Selleck was preparing for his role by working out with major league teams last season.

He said, "I sat in a lot of dugouts last year, including the Tigers - I was born in Detroit. I took batting practice and sat on the bench with the Yankees, Mets, Red Sox, Indians, Reds, Twins, Blue Jays, Dodgers and Angels.

"It was a dream come true. In many of those instances, I actually remained in the dugouts during games. Some of the players welcomed me. Some didn't.

"I really felt I belonged in spring training with Detroit when some of the guys put Atomic Balm (a fiery muscle salve) in my jock. If the players kid you, you know they like you.

"At the end of spring training at an exhibition game against Cincinnati, (Tiger manager) Sparky Anderson had me pinch hit. So I have a major league at-bat in spring training to my credit."

Asked how he performed in his only major league turn at the plate, Selleck laughed.

"As I like to remember it, I made contact with the ball four times," he said. "But they were all foul balls or foul tips and I eventually struck out. That pitcher was cutting me no slack. He was looking for a job.

"Just playing catch is a kind of male ritualistic thing. And every day with the Tigers I would warm up with Al Kaline, one of the coaches, who was my idol when I was a kid. He's a Hall of Famer. Talk about dreams coming true.

"But the spring training fans were brutal. The young pitchers, looking for a spot on the roster, and when some old actor like me starts hitting the ball off them they get embarrassed. So they were firing it up there and I was striking out. I even got hit a couple of times. The fans got all over me like a cheap suit.

"I was never more prepared for a movie role. I became a better baseball player because I attended team meetings and learned how major leaguers deal with each other.

"I can hit a long ball, so in the movie there aren't a lot of camera tricks. Any time I was required to hit a home run, if they gave me four or five pitches, I could hit one out. If you hit a lot, you can get consistent.

"In some sequences we had 38,000 extras in the stands in Nagoya. In one shot I had to hit what looked like a homer until it hooked foul at the last moment. And I actually did it."

Selleck is very proud of that.

He portrays a fading major league slugger who signs with a Japanese team, the Chinichi Dragons, to extend his career. The Japanese dub him "Mr. Baseball," hence the film's title.

"There's a real clash of cultures when the guy gets to Japan, which has been the case with real American players who go there," Selleck said. "It's easy to understand. We read about the culture clash every day.

"The atmosphere is so ripe for misunderstanding, even on the level of languages, which are based on different fundamentals. Ours is based on words, theirs on thoughts.

"A Japanese actor in the picture, who speaks English, sat in on one of my interviews. Afterward he said, `I enjoyed your interview and what I think you wanted to say. But the translator didn't understand the meaning and interpreted your words literally. A lot of people won't like how it came out.'

"Translators have to interpret and cross the cultural barrier. Most of them don't, which accounts for all the crazy quotes on both sides.

"There's a difference between Japanese and American ballplayers.

"I had no trouble communicating with them on the field. They have a real strong work ethic, but it's focused differently than American players. For instance a Japanese pitcher pitches every day. Not in a game, but he throws every day.

"To cure a sore arm, they have him pitch his way out. It doesn't work, but they think it does. They have guys duck-walk right after knee surgery to get back in shape.

"There's a constant butting of heads between my character, his manager and the rest of the team. But he learns a lot, and so do they in terms of things like taking someone out on a double play.

"They're happy when a game ends in a 15-inning tie so nobody loses face. Stuff like that. It's weird, but completly within the ethical standards of Japan, which drives my character nuts.

"I didn't bother with lunch while we were shooting in Japan. Instead, I'd take batting practice.

"A love of baseball runs in my family. My older brother, Bob, played ball with the Dodgers' minor league clubs," he said proudly. "Then he developed knee problems and left the game."

In addition to "Mr. Baseball," Selleck starred in the recent "Folks, " a father-son story in which his father is played by Don Ameche.

" `Folks' and `Mr. Baseball' are two very different pictures," he said. "I loved doing them both."