OK, I got a bit curious and looked this ride up. You're in trouble.
http://www.vueltapr.com/The_Tour/Route
1st day is 150 miles with around 2000ft of climbing, day 2 is relatively mellow @ 91 miles with 1500ft, day 3 is 134 miles with 2300ft.
I'd agree the climbs on their own aren't too bad, it's broken up reasonably well over the three days. But if you don't put *cough* time in the saddle, you're gonna be real unhappy at the end of Day 1.