Cathie,
We went to Tropicana Field to see the Yankees play the Devil Rays two years ago while we were staying at WDW. It took about an hour and 20 minutes to get to the stadium, which is in St. Petersburg, not Tampa. You take I-4 westbound to its end where it becomes I-275 and drive over the LONG bridge from Tampa to St. Pete. (I'm a bridge chicken.) Stay south on I-275.
I've pulled out a map I bought of St. Pete for the trip and it looks like it's exit 9 off I-275 for Tropicana Field. You'll want to double check me on that one though.
All in all, not a bad trip to get there. I had never been to a domed stadium before. It was kind of nice to sit in 72 degree comfort while it was about 100 degrees outside! Who are the
D-Rays playing while you're in Orlando?
Have fun at the game.