Matt Holliday. On the last year of his deal with the Cards with a team option for 2017, still hitting well but not so well he'd cost mucho prospecto, team isn't in immediate contention. If you're looking for a deadline deal to upgrade in left, the guy to go after is Holliday.
If we make 2 deadline deals, one for ESantana, one for Holliday, we'll have had an aggressive but very rational deadline and should be in good shape to contend.