This week, Rafael Palmeiro makes his first and only 2003 appearances at his old workplace, Camden Yards.

These are pivotal times for Palmeiro, now 38. He hit the 500th home run of his career in May and has 21 homers on the season, but was left off the American League’s All-Star roster. His days on the Texas Rangers roster could be numbered also. He’s been sharing time at first base this year with a rookie, Mark Teixeira. And, last week, the team got 21-year-old Adrian Gonzalez, a first baseman and the No. 1 overall pick in the 2000 draft, in a trade with the Marlins. The Southwest Sports Group, parent company of the Rangers, recently defaulted on a nine-figure loan, and Palmeiro’s name now comes up whenever talk turns to who will be axed to cut payroll for the historically underperforming franchise.

For all his big numbers—he’s averaged 33 homers and 106 RBI in his 15-plus-year career, either of which in any other era would guarantee him a spot in the Hall of Fame—Palmeiro has remained a rather anonymous player. In his six seasons with the O’s (from 1993 to 1998), he was overshadowed by Cal Ripken and Peter Angelos. Among the Rangers, Alex Rodriguez gets all the good ink. Raffy would have to cork his bat to get as much attention for his on-field feats

as this season’s other newcomer to the 500 Club, Sammy Sosa.

But while we’re on the subject of corked bats: Palmeiro has found another path to fame. Just as a lot of folks remember Joe DiMaggio not as the Yankee Clipper but as Mr. Coffee, among the masses, Palmeiro’s perhaps better known for his product endorsement than his play. All because of his decision last February to become the spokesman for Viagra, the prescription drug that, since its 1998 introduction, has become a billion-dollar annual earner for pharmaceutical Goliath Pfizer.

Palmeiro, who was paid a reported $500,000 to replace Bob Dole as Viagra’s top hawker, immediately became a punch line. First there were the late-night monologuers and sports-talk radio callers who had an easy time with the Palmeiro-Viagra teaming. Then the sportscentric comic strip Tank McNamara put in a Palmeiro story line. The worst abuse came when he went to Pittsburgh last year for a series of interleague games with the Pirates. A report in the Pittsburgh Post Gazette held that during Palmeiro’s trips to the plate, the stadium’s PA system blared “Boing!,” the house organist played “Pop Goes the Weasel,” and the video screens showed a spurting fountain.

Palmeiro initially wavered under the onslaught, denying through his agent, Fernando Cuza, that he ever needed what Viagra offered. But he quickly recanted that denial and eventually accepted his pitchman’s role and began to speak openly about the need to destigmatize erectile dysfunction.

Cuza now says that Palmeiro’s low-key nature may have been what prevented endorsement deals from coming the player’s way before Viagra and that the benefits from the campaign’s exposure could be long-term.

“What [the Viagra advertisements have] done is they’ve shown that he’s able to represent himself on the national media, that he’s very confident,” says Cuza. “This has put him in a certain level where other advertisers can say, ‘Hey, this is a mature, sophisticated player who has great camera presence.’”

Pfizer says it’s satisfied with the relationship, also.

“Raffy worked out well for us,” says Daniel Watts, a spokesperson for Pfizer. “We wanted to reach out to men of all ages. And though the incidence [of dysfunction] goes up as you get older, men in their 30s and 40s can have this problem, and we needed someone like Raffy who could talk about it. That gives men permission to say, ‘If he can talk about it, I can talk about it.’”

But as his playing career winds down, Palmeiro’s status as the face of impotence, along with Viagra’s place as the unquestioned king of Dysfunction Junction, are in jeopardy. Some of the most potent players in the pharmaceutical world have teamed up to try to take ’em down.

“Pfizer and Viagra are in real trouble, and they know it,” says John McCamant, editor of Medical Technology Stock Letter, a California-based newsletter that monitors, among other things, the erectile-dysfunction domain.

The two main threats to Viagra are Levitra, a drug cooperatively produced by Bayer Corp. and GlaxoSmithKline, and Cialis, the product of a joint venture between Eli Lilly & Co. and ICOS Corp. Both are expected to be approved by the Food and Drug Administration for sale in the United States by the end of the year. But neither waited for government approval before revealing that, like Pfizer, they would focus their market strategy on the sports world.

In May, the NFL announced that it had signed a partnership deal with Levitra that includes making Mike Ditka, the former Chicago Bears coach, its chief endorser. And Lilly/Icos disclosed last week that it had teamed up with the PGA to become the sponsor of the Western Open golf tournament beginning next year.

McCamant, however, says that in the end the battle will be won not on the playing fields but in the bedroom. And he’s predicting Cialis knocks Viagra out cold.

“Cialis is calling itself ‘the Weekend Pill,’ because [studies show] its effects can last so much longer than Viagra,” says McCamant. “So unlike the competitors, Lilly can tell men that they can just take this pill on a Friday and they’re good to go all weekend. What a pitch! Even I could market that.”

Pfizer’s Watts says Viagra will be up to the challenge.

“We’ve heard all about ‘the Weekend Drug,’” he says. “But the fact of the matter is most of us don’t make love for the entire weekend.” —Dave McKenna