San Francisco Giants right fielder Hunter Pence will undergo surgery to reattach a torn right hamstring tendon, the team announced on Friday . The procedure comes with an expected two-month recovery and rehab timetable, which means San Francisco will be without one of it key components at least through July and potentially deep into the month of August. Pence reportedly tore the tendon clean off the bone near the back of his right knee during Wednesday's game in Atlanta. Manager Bruce Bochy compared it to the hamstring injury suffered by Angel Pagan in 2013. Pagan's injury also required surgery and sidelined him for nine weeks. [Related: Johnny Cueto looks to keep Giants rolling against Cardinals ] Obviously, there's no good time to lose a valuable member of the roster. Pence's injury though came at a time when San Francisco was clicking on all cylinders, having won 15 of 18 leading up to Wednesday. When the Giants are playing well, it can usually be traced back to a handful of sources. Pence is one of those guys, not only because of his numbers, but because of the positive energy he brings to the clubhouse.