"This decision comes with mixed emotions, as we obviously have a deep history with and genuine fondness for Tucson," D-backs team president and CEO Derrick Hall said in a statement.
The D-backs have trained in Tucson since the club's inception. Their first Major League Spring Training in the city was in 1998.
The White Sox moved from a shared facility with the D-backs to Glendale, Ariz., this past spring, leaving just the D-backs and Rockies in Tucson. When the Rockies told Pima County of their intention to move around five weeks ago, the D-backs followed suit.
"With the current environment of Spring Training in Southern Arizona having led to the Colorado Rockies' recent and formal decision to relocate, we find ourselves in the undesirable position as the only MLB team operating there beyond 2010," Hall said. "We have narrowed down our options to a few we consider exciting and realistic opportunities, and continue gathering more facts and details with hopes of coming to an agreement quickly."
The D-backs' lease at Tucson Electric Park expires in 2012, but Hall said there was an out clause if they were the only team in town, which they would be with the departure of the Rockies.
The D-backs and Rockies plan on sharing a Spring Training facility in the Phoenix area. One of the sites most often mentioned and the likely frontrunner is the Salt River Indian Reservation located just to the west of the Loop 101 Freeway in Scottsdale.
Hall said there were three sites still "in play" at this time. Whichever location is chosen, private funds will be used to build the facility.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.