Dolphins activate Chris Culliver, promote CB Lafayette Pitts up from practice squad

Chris Culliver runs drills during practice Tuesday. DAVIE - The Miami Dolphins are calling on reinforcements in the secondary, which has struggled with coverage for most of this season.

Miami activated cornerback Chris Culliver from the team's physically unable to perform list, adding him to the 53-man roster on Monday. The Dolphins also promoted rookie cornerback Lafayette Pitts up from the practice squad.

To make room on the 53-man roster for both cornerback Miami waived defensive tackle Chris Jones, and cornerback Chimdi Chekwa was waived injured.

Chekwa, who injured his right knee in Sunday's 27-23 win over the New York Jets, will likely be placed on injured reserve. Jones played in seven…