When Angel Pagan discussed the small tear in his left hamstring tendon over the weekend, he said that he would miss about six weeks if the injury required surgery. It turns out that he'll have to miss significantly more time. Giants manager Bruce Bochy told Andrew Baggarly of CSNBayArea.com that Pagan will undergo surgery tomorrow and is expected to miss 12 weeks. In other words, he's at risk for missing the rest of the regular season. That's a tough blow for the defending World Series champions.