From the Arizona Daily Star: I think this is just speculation.
Look to Cincinnati:
Reds likely replacement if White Sox leave town
If the White Sox ultimately bail out of their Tucson spring training commitment, the most likely replacement is the Cincinnati Reds, who, ironically, filled the White Sox's vacated spring spot at Ed Smith Stadium in Sarasota, Fla., eight years ago.
The Reds have asked the Sarasota City Commission to build a $48 million stadium/complex or they will bolt that city when their lease expires in 2008. So far, politicians and developers in Sarasota have been unable to meet the Reds' requests. The Reds said they will sign a 20-year lease if the stadium is built.
Capacity at Ed Smith Stadium is a mere 7,500; the Reds fill it only if the Yankees and Red Sox make their one spring visit there.
No matter what happens with the White Sox, one issue remains: Tucson probably isn't yet large enough to fully support three spring training teams. The Rockies are often fortunate to draw 3,000 and until the White Sox won the 2005 World Series, they were often an afterthought and surely felt that way.