ESPN's Adam Schefter is reporting that the Detroit Lions are one of three teams currently over the NFL salary cap. According to Schefter, the Lions, Houston Texans and New York Giants are all around $700,000 over the salary cap right now.
The good news is that the Lions have until Wednesday to get under the cap. The bad news is that if they can't restructure contracts to get under, they will have to move somebody. From Schefter:
Houston, Detroit and N.Y. Giants are all roughly $700,000 over NFL's salary cap, according to league source. Houston can take their cap exception from the Redskins and Cowboys and get under the cap, but the Giants and Lions will have to make a move or restructure contracts to get under cap. They have until Wednesday to do it.
The Lions restructured a few contracts before the start of the 2012 league year in order to free up cap space. My guess is that they will do something similar again instead of trading or releasing somebody.