While president of the United States in the early 1900s, Theodore Roosevelt employed his famed "Big Stick diplomacy" in Santo Domingo, Dominican Republic, sending in troops to help protect American interests in the area.

A century later, however, the man who ranks as one of that city's most famous natives — Mariners third baseman Adrian Beltre — is neither speaking softly nor carrying a big stick.

After concluding an 0-for-12 series against the Angels on Wednesday — which dropped his batting average to .221 — Beltre declined for the second straight day to talk with reporters, leaving it to others in the Mariners clubhouse to state his case for him.

"I'm sure he's thinking exactly what the fans are thinking: 'What about this guy?' " said John Boles, a special assistant to Mariners general manager Bill Bavasi who spent the past three years with the Los Angeles Dodgers, Beltre's former team.

"I'm sure he's trying so hard to please the organization and the Seattle fans, and when you do that, you don't play relaxed and confident. When you start trying to hit the five-run homer every time up, you're just doing damage to yourself. But this guy has talent. I'm sure he'll start to pick it up."

And, sure, everyone can agree that 28 games is far too small a sample to determine much of anything. It sounds alarming, for instance, to note that Beltre, who has just two home runs and 16 runs batted in, is on pace for just 12 homers this season. But that makes about as much sense as using the first quarter of an NBA game to project the final score.

Still, the Mariners (12-16) need Beltre to break out of it sooner rather than later. They are heading into a 12-game stretch against the Yankees and Red Sox, and already are five games behind the Angels in the AL West standings. If the losing continues, they could quickly fall into dangerous territory.

"It's not getting any easier going to Boston and New York," said second baseman Bret Boone.

Even if the Yankees are struggling as mightily as the Mariners.

ROD MAR / THE SEATTLE TIMES "He'll get it turned around," John Boles, special assistant to the Mariners GM, says of Adrian Beltre. "And when he does, look out."

"Hopefully, we can take advantage of that," said first baseman Richie Sexson. "If we can come back here maybe two games under [.500] we will be feeling pretty good about ourselves."

For the long-term good of the team, nothing would be better than seeing Beltre revert to 2004 form. But while he was regarded as one of the biggest prizes on the free-agent market last winter, he didn't come without risk.

A columnist for CNNSI.com, for instance, wrote in March that the Mariners' signing of Beltre was the biggest gamble of the season, pointing to Beltre's uneven history.

Beltre hit the jackpot by clubbing 48 home runs last season — tied with Mike Schmidt for the most ever by a third baseman — and hitting .344. But that homer total was more than double his previous best (23 in 2003), and he had never before hit better than .290.

Conventional wisdom was that Beltre, who just turned 26, had finally turned in the breakout season expected since he signed with the Dodgers as a 16-year-old in 1996.

But baseball history is also full of one-hit wonders — Norm Cash averaging .361 in 1961 and never better than .286 again, or Davey Johnson slugging 43 homers in 1973 and never more than 18 again.

The Mariners are hoping more realistically that Beltre will settle in at a .300, 30-homer, 100-RBI type of pace.

And there are lots of other obvious reasons for Beltre to be slumping early.

He's adjusting to a new park, one generally regarded as one of the hardest in baseball in which to hit. He's surely feeling the pressure of trying to justify his huge salary. He's adapting to a new league.

And he's battling his own history of being a slow starter — he's a career .261 hitter with 60 homers and 220 RBI before the All-Star break, .287 with 87 homers and 290 RBI after it.

"He's been in Los Angeles his whole career, he's changing to a new city, a new team, new teammates. He's signed a big contract," Boone said. "I'm not saying those are affecting him, but there are a lot of things that can affect you in a lot of different ways."

A sign that Beltre might be trying to live up to his contract is some impatience at the plate. Last year, he walked a career-high 53 times. So far this year, he has walked just three times, putting him on pace for just 17 for the season.

As for switching leagues, Beltre arrived with a few warning signs. Before this season he had hit .198 (27 for 136) in his career in American League parks in interleague play, with just four home runs.

But Boone and Sexson, who have each seen significant time in both leagues, scoffed at that being a real issue.

Sexson said it's not so much playing in a different league that requires adjustment but playing against different teams.

"I faced Paul Byrd [the Angels pitcher who beat the Mariners on Wednesday] in the National League," Sexson said. "So it's not like I haven't seen him before. But he might change how he throws, because different teams have different philosophies on how they throw guys. That's more of a change than anything."

And Boles pointed out that Beltre hasn't let his hitting impact his fielding. He said Bavasi told him recently that Beltre has already saved more runs with his glove this year than Seattle's third basemen drove in a year ago.

"If our biggest worry is Adrian Beltre, then we are leading a pretty good life," Boles said. "He'll get it turned around. And when he does, look out."

Bob Condotta: 206-515-5699 or bcondotta@seattletimes.com