Will Padres’ September song have Chase Headley playing Dodgers’ tune?

The calendar has turned to September — or, as they call it in San Diego, football season. The Padres are 19 games out of first place. They finished 18 games out last year, 23 the year before that, 20 in 2009, 21 in 2008.

For Chase Headley, this September will be his sixth in San Diego. One pennant race. No playoff games.

Oh, yeah, he pays a little bit of attention to our hometown team.

“You can’t help but see what’s going on in L.A. and be impressed,” Headley said, “with all the talent they have collected and to see how it all has fit together.

“In the beginning, it didn’t seem like it fit together at all. Now it seems like they’re playing at — I’m not a baseball historian, but it’s been a historic pace.”

Indeed it has. As the Dodgers and Padres play a weekend series at Dodger Stadium, the Dodgers are rolling toward the playoffs. The Padres are slouching toward elimination, and toward a decision about Headley.

This time last year, he was the best player in the National League. Headley was the NL player of the month in August, and again in September, hitting 19 home runs and driving in 63 runs over the final two months. Miguel Cabrera won the triple crown last year and might do so again this year, but he never has driven in 63 runs over consecutive months.

The Padres insisted they would win with Headley rather than trade him for a bushel of prospects. Now they are fighting to stay out of last place, and he is batting .240, with the next-to-lowest slugging percentage of any regular major league third baseman.

Headley has a .699 on-base percentage plus slugging percentage. Juan Uribe, who started the season backing up Luis Cruz for the Dodgers, has a .722 OPS.

“I know this isn’t the kind of player I’m going to be,” said Headley. “It’s a tough situation. It’s a frustrating situation. In no way do I think the game has passed me by.”

Headley will be fine. The Padres are cursed with a variety of options for him, none of them very good.

It probably did not help that the Padres rushed Headley back from the broken thumb that cut short his spring training, installing him in the lineup after a minor league rehabilitation assignment that lasted just 12 at-bats. Still, he is a switch-hitter with power, a solid defensive player, and generally durable.

He might never again be as good as he was last season, when he led the NL with 115 runs batted in. But he and the Padres agree there is a happy medium between then and now, a middle ground that would make most any team happy, in an era when quality third basemen are scarce.

“I take the longer view of Chase,” Padres General Manager Josh Byrnes said. “He is a very good player.”

What Byrnes will not say is what he said last year. He will not say the Padres are positively, absolutely not trading Headley.

The Dodgers and the Angels could use a third baseman, not to mention the New York Yankees, San Francisco Giants, Boston Red Sox, Philadelphia Phillies and St. Louis Cardinals. But, with Headley eligible for free agency after next season, a team that trades for him would risk losing him after one year. That could limit the Padres’ return.

The Padres would prefer to sign Headley to a new contract. He is 29, which means a long-term contract carries the risk of paying a player as his performance starts to decline.

The Padres almost certainly cannot afford that — not, at least, without the hometown discount Headley all but says he would not grant.

“My first choice would be to stay here,” he said. “I love our coaching staff. I love a lot of the guys here. That said, you have to at least understand where you are positioned in the market. It doesn’t benefit myself or the other players to go out and sign a deal just to sign a deal, without it being a good deal.

“I’m not actively trying to get to free agency, but trying to get what you are worth is important. It would be foolish not to at least pay attention. I’m not going to sell myself short.”

Headley also wonders if the Padres would make the same offer this winter after a .240 season that they would have made last winter, when he finished fifth in the NL MVP race behind Buster Posey, Ryan Braun, Andrew McCutchen and Yadier Molina.

“Most likely, if I do a deal in the offseason, there is a chance it could be potentially lower than a deal I could have done last offseason,” Headley said. “I don’t know until we look at it. I know this season isn’t the statistical norm.

“Do I want to sign a bad contract coming off a bad year? Every season impacts the business side of it. It would have been great to have another season like last season. That’s not the case.”

The Padres are having another season like last season, and like too many others in their recent history.

“At this stage of my career, I want to win,” Headley said.

Headley says the Padres can win, and their minor league system is pretty good. But reality wears blue these days. Ron Fowler, the Padres’ executive chairman, told reporters last week that the team would increase its payroll by more than 20% next year.

That still would leave the Padres spending less than half what the Dodgers do. For the sake of the beaten-down San Diego fans, it would be nice to see the Padres pay market value to retain one of their own.

But those fans are painfully aware of what market value too often means for a homegrown star: Adrian Gonzalez has been playing first base this weekend at Dodger Stadium, against the Padres.

bill.shaikin@latimes.com

Twitter: @BillShaikin