Evan Longoria left last night's game against the Baltimore Orioles early as a result of a strained oblique muscle. St. Pete Times beat reporter Marc Topkin is reporting that Longoria had felt sore in the batting cages earlier that day, but tried to play through the soreness regardless. It got worse as the night went on, though, and he eventually had to be removed from the game.
While Longoria is saying he expects to miss only a week, Joe Maddon has said they'll reevaluate Longoria on Sunday to determine if he needs to take a stint on the 15-Day Disabled List. They intend to be cautious with Longoria, as it is the beginning of the season and he's the Rays' franchise player.
In Longoria's stead, Maddon will likely turn to Elliot Johnson and Sean Rodriguez to fill in at third base. It's also possible that Maddon may be creative like he was at the end of last night's game, playing Johnny Damon at first base and moving Dan Johnson over to third. This likely isn't the Rays most optimal defensive alignment, though, so my assumption is Maddon will simply use Johnson or Rodriguez depending on the opposing pitcher.