-- Plenty of thoughts run through your mind when you are 39 years old and fastballs are getting by you with more frequency, when you are toiling on a fourth-place team in the dog days of summer. Plenty of thoughts run through your mind, not all of them pleasant, when all those things are true, and at the same time you could take your 542 home runs and walk away right now with your Hall of Fame credentials still solid whether you ever take another swing.

"A lot of stuff has gone through my mind," Rafael Palmeiro said Sunday morning as he got ready to take the field for the Baltimore Orioles that afternoon at Yankee Stadium. "But the main thing is to stay focused on what I need to do now. I'm not going to hang it up. I can still play the game.

"I'm just struggling offensively. It doesn't mean I'm going to quit. I'm not going to quit. And I'm going to figure it out, because I can still hit."

And that afternoon, as if to prove his point, Palmeiro flicked his arms with that effortless, picturesque motion, and put two excellent swings on two chump pitches, producing a rocket-single that almost knocked over the right field wall and a home run, deep to right.

The homer was only Palmeiro's 14th -- nothing to be ashamed of but a far cry from the 38 he hit last season for the Texas Rangers, the ninth year in a row Palmeiro had hit at least 38. His batting average sits at .251, nearly 40 points below his career average. Teams now routinely thwart him by shifting an extra infielder to the right side of second base.

With all this going on, and with the Orioles holding a 46-57 record entering Tuesday's day-night doubleheader against the Seattle Mariners at Camden Yards, Palmeiro seemed not a bit surprised or offended when a reporter asked him if he has considered the possibility this is the beginning of the end.

"It's hard not to consider it, because I am 39 years old," he said. "And eventually it doesn't matter who you are. Players who were better than me decline and eventually have to get out of the game. But with me, I think it's more mechanical than anything. I know I'll get it, and when I get it I'm going to be as productive as I've been before. . . . It's not like I'm being overmatched or anything. There's just something off in my hitting that's not allowing me to be successful like I want to be."

One scout who has seen the Orioles recently stopped short of saying Palmeiro appears washed up. "But he has lost some bat speed," the scout said, "and he's so pull-happy, you can easily stop him with the shift."

Palmeiro believes the shift -- which he first started to see last season -- is at the root of his problems. When he sees the shift, it sets off a series of calculations in his head about changing his stance, keeping his hands farther back, trying to guide the ball to the left side -- in other words, things he never used to think about.

"I used to just go to the plate, see the ball and hit it," he said. "Now, sometimes I'm letting myself be affected by the shift. I've got to get back to my old approach."

Everything was supposed to have gone so differently. Palmeiro, who produced five excellent seasons for the Orioles during the glory run in the 1990s, was one of three high-profile free agent signings the team made this winter -- along with shortstop Miguel Tejada and catcher Javy Lopez -- designed to overhaul the offense and move the franchise a step closer to returning to those glory years.

"I had no reason to believe I would have any type of drop-off or anything," Palmeiro said. "I worked harder than ever in the offseason. I was anticipating having my typical year."

Instead, Palmeiro has slowly crept down the lineup -- from the cleanup spot, where he started the season, to No. 5 for much of June and July, and lately to No. 6, and that's not to mention days like Saturday when he was given a day off against a right-handed pitcher -- and the Orioles have remained well out of contention.

In recent days, Palmeiro, who signed a one-year, $4.5 million deal, also has had to deal with speculation that he might be traded to a contending team. While Palmeiro does not have no-trade privileges in his contract, he has a "gentlemen's agreement" with owner Peter Angelos that he would not be traded against his wishes. And in any case, Saturday's trade deadline passed without anyone approaching him about a trade.

Still, Palmeiro's future with the Orioles could be decided based on how often he appears in Manager Lee Mazzilli's lineups. Palmeiro's contract has an option that vests if Palmeiro plays in 140 games in the field -- in other words, appearances as designated hitter do not count.

Should he continue to get more frequent days off, Palmeiro could be left to choose between searching for another job or retiring and letting the clock begin ticking until he is eligible for the Hall of Fame in five years -- things that have crossed Palmeiro's mind, but nothing he is ready to consider now.

"I'm going to keep going at it, man. I'm going to put together a good streak," he said. "I'm going to do it. I've done it before. I'm not going to quit doing it now."

Rafael Palmeiro, one of three high-profile offseason acquisitions expected to add punch to the Orioles' offense, is hitting .251, nearly 40 points below his career average.