Although the Mets have spoken more highly of Ruben Tejada in recent weeks than they did at the beginning of the offseason, it wouldn't be a surprise if the team still wanted to acquire a starting shortstop. Enter the Mariners. According to Adam Rubin, Seattle is likely to trade one of Nick Franklin or Brad Miller before the beginning of the season.
Franklin is 22 years old and was drafted in the first round of the 2009 amateur draft. A very good hitter in his minor league career, he debuted last year and hit .225/.303/.382 with 12 home runs in 412 plate appearances. But he played second base in 96 games and only played three at shortstop. There's doubt that he's capable of playing short at the major league level, though he played more short than second in the minors.
Miller is 24 years old, was drafted in the second round of the 2011 amateur draft, and also made his major league debut last year. He hit .265/.318/.418 with 8 home runs in 335 plate appearances. Although he might not look like a top-notch defender, there seems to be less question about whether or not he can stick at short. He played 68 games at short last year and just 13 at second.
If the Mets were to attempt to trade for either player, it's unfortunate that Seattle has no need for Ike Davis or Lucas Duda—not that either player would net one of the shortstops alone—as they're already stacked with first basemen and designated hitters. That probably makes Wilmer Flores less valuable to them, too, assuming they see him as a trade target in the first place. So unless the Mariners covet one of the Mets' position player prospects, the Mets would probably have to part with a young pitcher or two to make a trade happen.