Lincecum threw 113 pitches today in 7 innings against the 29th ranked offense in MLB. His numbers weren't terrible, but he hasn't had a strong outing in nearly 4 weeks.
Lincecum's pitch count and early exits have a ripple effect. The #4 and #5 starters usually don't go as deep in games, which means the bullpen is sometimes overworked by the time the #1 starter takes the mound.
When your #1 starter isn't logging the innings the way he's expected, the pen is maybe more likely to collapse.
Jimenez is off to a fantastic start, and historically is stronger in the 2nd half - we'll see if he can keep it going the rest of the season.