Best way to improve a worn out bullpen

What it the best way to help out a tired bullpen? Starting pitchers doing their job and pitching deep into a game. Jake Westbrook did just that tonight throwing a complete game shutout and giving the bullpen a night off.

Travis Hafner, who ended last nights game with a two run homer, walked and scored in the second inning and then hit a grand slam in the next inning to account for all the runs tonight. I have a hard time accepting the idea of a DH being the league MVP but if Hafner keeps this up he will merit strong consideration. A quarter of the way through the season and he is averaging nearly a run and an rbi a game.