CHICAGO -- "Hi, I'm Greg Olson," said Greg Olson, walking up to Baltimore Orioles Manager Frank Robinson at the All-Star Game workouts at Wrigley Field.

"Yeah?" said Robinson, as he looked at the stocky catcher, one of the oldest rookies in the majors at 29 years 10 months. "You don't look like the Gregg Olson I know."

For a split second, looking at the Hall-of-Famer's grim put-on expression, Greg William Olson of the Atlanta Braves thought his little joke about pitcher Gregg William Olson of the Orioles had bombed. Then Robinson added, "But if you want to come over to my team, you're more than welcome."

Words Greg Olson never dreamed he'd ever hear any major league manager say.

That's just one of a hundred sweet, giddy, borderline-unbelieveable stories that Olson, the NL's backup catcher, will tell for the rest of his life.

Olson, you see, is the most unlikely all-star in baseball history. Period. Case closed. Nobody close.

He may also be the happiest.

"I thought this making-the- all-star-team had sunk in," he said bashfully. "But once I went out there on the field, I got so numb. I saw the fans. The whole grandstand looked pink with those {give-away} hats. I never knew there were so many sportswriters in the whole world. Then I went out, broke a sweat and hit a few balls. It exceeds my wildest dreams. And my dream was that it would be the ultimate. For something to exceed the ultimate, well, that tells you it's above and beyond anybody's belief."

Sportswriters turned to each other to make sure they'd gotten all of that right.

Greg Olson -- The Other Olson here -- has a right to be euphoric yet glazed, grateful yet proud, out of his element yet soaking up every second. "Home run hitting contest in five minutes," the clubhouse man whispered to Olson at one point. "Thanks," answered Olson, definitely a spectator in that one. "I don't want to miss anything."

Olson played eight years in the minors after three years of college ball. And he was never even a minor league all-star. He was released by the Mets and, last year, the Twins. Last September the Twins -- with an unlimited roster -- chose to be the only team in baseball with only two catchers. They decided they'd rather have nobody -- an empty seat -- than call up Olson. "What does that tell you?" he said.

"An old football coach that I respect asked me, 'When are you going to get out of that game? It's just too tough. Too many things have to go right,' " said Olson, laughing. "And he told me that five years ago."

So last winter Olson and his wife decided this was his last season. Make the majors or hang it up. "Sell something," Olson said. "Maybe take over my father's life insurance book."

Olson started this year as a walk-on (a non-roster invitee) for Atlanta -- the worst team in the NL. Did he make the club? No way. He started the 1990 season at Richmond.

No player in history had ever made an all-star team after starting the year in the minors. Until Olson last week.

How did Olson, with a career major league record of two at-bats, get to The Show. And then this Show of Shows? Try luck, for starters. A series of odd circumstances -- including a player cut, a player retired and a player disappointing -- forced him up to the majors on April 10 after six days in Class AAA. Even then he was the last man on the team: the 15th-inning pinch hitter, the mop-up backstop. Finally, with Braves catchers dropping like first lieutenants, Olson got to start.

Now, Atlanta can't get rid of him.

Let it be emphasized, amidst the chest-deep irony, that Olson is here because he deserves it. He's always been able to catch and he's hitting .289 -- about 100 points more than anybody in baseball's hierarchy had imagined possible. His six homers and 25 RBI in 166 at-bats also are nice. When Benito Santiago got hurt, the NL turned to Olson as the logical -- although utterly incredible -- choice.

Will he get to play? Perhaps if the game goes 21 innings or starter Mike Scioscia is struck by lightning.

Olson says he'd love to bat against The Other Olson. "It would be good for baseball. And fun," he said. "I just went to meet him. Actually, if I faced him, it would probably be more fun for him. I hear he throws 90 mph with a nasty curve."

It's more likely that, unless the camera pans over him during the National Anthem, you won't see Greg Olson on Tuesday. "I'll be the one praying," he said.

In fact, as rarely as the Braves get on network TV, some fans may never see him. "I'll never be here again," Olson says, laughing, looking around the all-star locker room at Will Clark and Darryl Strawberry. "Well, you know, probably not . . . realistically speaking."

Olson may have been the last person to fully believe that he was an all-star. "One of our {beat} writers passed me in the tunnel and said, 'How ya doing, all-star catcher.'

"I said, 'Are you sure?'

"At first, I didn't know whether to jump up. I almost felt like crying. I wanted to be alone for a few minutes. Then I wanted to be around my friends, so I went in the clubhouse and everybody congratulated me. . . . It's even been a tear-jerker for me."

Nobody better try to take the all-star ring away from this Greg Olson, or the ball autographed by the whole team. "I was here before anybody at 9:30 a.m. to sign those two dozen {official All-Star Game} balls," he said. "My name was the first one on every one."

Unfortunately, Olson could not take part in another all-star tradition -- signing his baseball card for fans.

"The only card of me is a Major League Debut Card {an obscure series}. And I'm in a Twins hat," he said. "I'm probably the only guys who's played in this game who didn't even have a {real Topps} baseball card."

For the moment, let's do what Greg Olson says is the key to baseball: pay attention only to today. "Everybody says it. Nobody does it," he said. "Last year I was scuffling bad down at Portland. Went one for 32. Hitting about .225." A friend told him: "You got to learn to think about today. Don't try to get 10 hits this week. Just one in your next at-bat."

The pressure at the plate popped. And hasn't returned.

"I couldn't be having any more fun. . . . Great names this way. Great names that way," said Olson, who's been getting 50 phone calls a day. And talking to everybody. "When I was seven years old, I had my picture taken with Rod Carew. Me grinning. Him looking the other way. You know how players love Picture Day. I kept that snapshot on my wall I don't know how many years. . . .

"You dream things -- like that you could be MVP of the World Series," said Olson, aware that such one-week flukes have happened to Brian Doyle and Rick Dempsey. "But I've never even thought of being an all-star."

But he is. And sharing a locker on Old-Timers Day with Robin Roberts.

You know, Robin Roberts?

Olson expression is blank. Worried.

Won 20 games six years in a row.

"Oh, yeah," said Olson, grinning. "I knew that."

Roberts better watch out. An autograph request may be coming up.