I did some rummaging through Westbrook's career stats and what I found was a good indicator for this Sunday against Green Bay. Since 2003 Westbrook has only faced the Packers 5 times while with the Eagles. He was not active for one game in 2006, so I took that one out.
Brian Westbrook Vs Green Bay has him 3-1 from 2003 to 2007, if he had played a down in 2006 it would be 4-1. His first outing against the Pack was forgettable with 5 att for 1 yd in 2003, after that it gets interesting. In 2004 Westbrook carried the ball 12 times for 37 yds however he hauled in 11 receptions for 156 yds and 3 TD's. In 2005 Westbrook rushed 20 times for 120 yds and 1 TD he also added 4 receptions for 11 yds. The lone loss he possesses against the Pack was actually not a bad outing for him with 20 Att for 85 yds and 6 receptions for 46 yds.
The major key I see in his winning stats Vs his losing stats is a touchdown when Westbrook scores he is more likely to win. So it seems even though Green Bay holds the series record with 33 W to the 49ers 26 and there being one lone Tie we have an ace in the whole against the 7-4 Packers.