If you somehow get another night off for Matzek it's kinda tough to find a reason not to replace Newk with Santana other than the fact that you can't bring him back until Friday because of the 10 day rule.
I'm as big a fanboy as they come - meaning I'm always Jonesing to see our prospects make it - but I'm not interested in guys like Newk and Wright being anywhere close to the active roster this deep into a playoff race if it can possibly be helped. I'm all for using them to burn innings in April, May, and June when the pressure isn't escalated, but I'm not 100% sure I wouldn't rather see Smith inherit a bases loaded situation in the 9th than have Wright or Newk pitch meaningful innings.