Michael Martinez, Image- Jay Floyd Following a pair of roster moves on Saturday, in which the Phillies traded veteran infielders John McDonald and Michael Young to playoff contenders, vacancies on the big league roster have been filled with the returns of Michael Martinez and Cesar Hernandez , as the duo has been promoted from Lehigh Valley. Martinez, who turns 31-years-old this month, has posted a .300 average along with three home runs and 21 RBI for the Triple-A IronPigs in 71 games this year. Conversely, the switch-hitting Dominican sported a .171 average in 21 big league contests over several stints with the Phillies this season. Hernandez, who projects as one of the best Phils positional prospects, was an All-Star second baseman this season but has been dabbling in the outfield quite a bit of late. His offensive numbers in the developmental ranks (.314/.378/.406) are much more impressive than his defensive performance at the new positions (four errors in 64 chances on ...