The Oakland Raiders and St. Louis Rams are seriously exploring a move to Los Angeles for the 2015 season, but only one of them could play in the preferred location of the Rose Bowl.
While the Pasadena government has enacted changes in recent years that would allow the number of games played at the Rose Bowl to increase as well as secure the necessary infrastructure to house an NFL team on an interim basis, it could not do so for two teams seeking to play there for a few years under such circumstances.
The NFL prefers to have two teams move to Los Angeles at the same time to share the risk and rewards associated with stadium development.