Ya gotta win all you can, no matter who you are playing until you are mathematically eliminated.
Let the other teams worry about each other. I can see the point of screwing the cubs though.

Cards first--always. The last thing I want to see is a Cubs divisional win, but if things work out that we do crush the Crew, that puts us back in contention as well (as long as Cincy takes a game or two from Chi). I cannot hope for our boys to lose, no matter the results for another team. Besides, not being psychic, I am loathe to assume that both the Crew and Cubs will continue to play at the levels they've shown so far. Perhaps the Crew is running out of gas. Perhaps the Cubs have peaked too soon--or will experience a bout of DL-itis--and will limp thru the final month. Perhaps the Cards are just coming into a stride of sorts that will pay off big. I'm guilty as anyone of pretty much giving up on the season, but there is a lot of baseball yet to play. If the Crew sweep us or take 3 of 4--and the Cubs sweep Cincy and continue winning against the Phils and Mets, well, I do believe that's it--but that's a tall order for them as well. If they falter and our boys gain some consistency of health and play, we may yet have a chance of catching the Cubs. Ending the season ahead of Chicago but below Milwaukee would be a meaningless but satisfying victory I would be okay with. Whatever the case, we'll all know fairly soon if any of this is still possible.

It's more a question of what is best for the Cards future.  I could really care less who wins the division if it's not going to be the Cards.

I'm more concerned that IF they win the series vs. the Brewers that they stand pat at the deadline and we are in for more of the same next year.

That is what worries me.