After being one of the top offensive shortstops with the Arizona Diamondbacks from 2007-2010, Stephen Drew suffered through two mediocre and injury-prone seasons in 2011 and 2012 with the D'Backs and Oakland A's before rebounded greatly for the Boston Red Sox in 2013. Drew hit .256/.333/.443 for a 109 wRC+ and posted 3.4 fWAR in 2013.
Drew is a good defensive shortstop and the numbers back that up, which is a change from earlier in his career when he rated terribly at the position. As for his bat, the numbers look good on the surface but seem suspect when examined further. Drew hit .283/.367/.491 (127 wRC+) at Fenway Park, but just .222/.295/.322 (88 wRC+) on the road. Drew also had some big platoon issues in 2013, as he hit .284/.377/.498 (137 wRC+) against right-handed pitching and .196/.246/.340 (53 wRC+) against left-handed pitching, with 55 strikeouts in 155 at-bats. For his career, Drew has a 105 wRC+ against righties and a 74 wRC+ against lefties. The issues have become so pronounced that the Red Sox have used Xander Boegarts to pinch hit for Drew against lefties.
It's still not clear if the Red Sox will tender Drew a qualifying offer. If he does get one, the Mets would have to give up a second round draft pick to sign him. In any case, Drew is likely to receive a multi-year deal from someone. His market value will likely be tied closely to fellow free agent shortstop Jhonny Peralta. It's pure speculation at this point, but a guess for Drew's contract would be an average annual value of $8-$10 million per year on a three- or four-year deal.
Given the "production" the Mets received from the duo of Omar Quintanilla and Ruben Tejada in 2013, any free agent shortstop would represent a colossal upgrade for the Mets, and Drew is the second best free agent shortstop on the market. Nevertheless, the concerns about Drew's inability to hit lefties and his poor road numbers can't simply be waved off. Drew also has health concern, as he missed 17 games with hamstring tightness from late June to early July. One can't afford to be nitpicky at the shortstop position, though, and if the choice is between Stephen Drew or what the Mets put out there in 2013, the decision is easy.