The Dolphins' front office spent part of Thursday speaking with the Houston Texans about quarterback David Carr and investigating all aspects of a possible trade for the former first overall pick in the 2002 draft. Carr ending up in Miami is not a certainty. But it is a possibility that speaks to Miami's uncertain quarterback situation. The team's interest in Carr, and even in Kansas City quarterback Trent Green, coupled with coach Cam Cameron's cautious words when he last spoke about Daunte Culpepper, indicate that Culpepper is not assured of being the team's starter in 2007.