Almost immediately after the Braves decided to trade Mark Teixeira on Monday, the Diamondbacks emerged as the apparent front-runner to acquire first baseman. At least two other clubs are in the mix for Teixeira, major-league sources say, but those teams might only be backups for the Braves if their talks with the Diamondbacks fail to progress. The Dodgers and Rays also are among the clubs that have shown interest in Teixeira, and both have young players who interest the Braves.