San Diego third baseman Chase Headley is the ideal candidate to help revive the Yankees’ aching lineup. It would be so easy: You move Kevin Youkilis to first, install Headley at third, and worry about the geriatric crowd when they return. The Yankees have no idea what they’ll get from Mark Teixeira and Alex Rodriguez this year anyway. There is but one problem with this plan: it seems clear that Chase Headley is not for sale. San Diego is in a holding pattern with its best player, leaving New York to look elsewhere (major league sources suggest the Houston Astros, and we’ll get to that in a moment). Padres general manager Josh Byrnes has said publicly that he is not breaking up his team right now, and that does not appear to be spin or strategy. One high-ranking National League West executive in regular contact with Byrnes said that the public and private stances match. “Headley is not going anywhere,” the executive said. “Not right now. They’re going to see how the team plays first.” The Yankees know, however, that they should keep Byrnes’ phone number handy in a few months. People familiar with the Padres’ thinking say that the team has not yet settled on a long-term strategy with Headley, and in the next 12 months both a trade and extension are possible. Some evaluators are not yet certain that Headley’s career year in 2012 represented a permanent leap forward. The only sure thing at the moment is that the Padres are keeping him this spring. So where can the Yankees look? As mentioned above, keep an eye on the Astros, who have depth at first base, in particular. Former Tampa Bay Ray Carlos Pena is set to become the first designated hitter in franchise history, but he should also be expendable -- especially considering the team’s rebuilding strategy, and minimal expectations for this year.