Tyler Pastornicky’s opportunity to fill in as Atlanta’s starting second baseman proved to be short-lived. Early Friday afternoon the Braves announced Pastornicky will undergo season-ending left knee surgery to repair the damage he suffered during a collision with Jason Heyward on Wednesday night. An MRI exam performed on Thursday showed Pastornicky tore the left anterior cruciate ligament in his left knee. A timetable for recovery was not immediately provided. The Braves have filled Pastornicky’s roster spot by purchasing Phil Gosselin’s contract from Triple-A Gwinnett. Gosselin could simply provide depth while Paul Janish serves as the everyday second baseman in the absences of both Pastornicky and Dan Uggla. When Dan Uggla agreed it was time to undergo LASIK surgery and consequently begin a disabled list stint late Tuesday afternoon the Braves promoted Pastornicky from Gwinnett with the expectation he would serve as the starting second baseman in place of Uggla who will not be eligible for activation until Aug. 28.