With his promotion to the Nationals, Anthony Rendon is sure to draw plenty of interest from mixed-league owners because he should get regular starts at second baseman. That means that Nick Franklin is no longer the latest prospect to join the ranks at the position, but he's still widely available and no less valuable in Fantasy than Rendon.
Since the Mariners made Franklin their man at 2B, he has shown the same patient approach he displayed in the minors, averaging 4.0 pitches per plate appearance, and he's even had a two-homer game. Owners shouldn't expect more than moderate home run power from Franklin, but he can provide doubles along with a high batting average and on-base percentage. Although Rendon is probably the better bet for homers, Franklin has the better potential for steals.
Given Rendon's injury history and relative lack of professionial experience, I'd prefer Franklin as my second baseman in standard mixed leagues. He's still owned in only 53 percent of the leagues on CBSSports.com, so in those formats, you should still be able to get him.