The release of Patterson will save the Dolphins about $5 million in cap space before Tuesday's start to free agency. Patterson began the 2013 season as a starter but because of nagging injuries played in only six games. He was put on injured reserve in December with a groin injury.
The 26-year-old Delmas was released by Detroit with one year remaining on his contract in February, in part due to having a cap number of $6.5 million in 2014.
The No. 33 pick in the 2009 draft by the Lions, Delmas played in 65 games for Detroit over five seasons, making 328 tackles, six interceptions and forcing two fumbles. He also had five sacks and four fumble recoveries.
His knees were chronically an issue for him and limited him to typically one day of practice a week in 2013. The plan was instituted, though, to make sure Delmas would hold up throughout the season and he played in every game for Detroit and had a career-high three interceptions.
Delmas was often considered the emotional leader of the defense and would routinely be one of two men, along with former Lions receiver Nate Burleson, speaking in huddles before games. Coincidentally, both Burleson and Delmas were released on the same day.
"He is leader on and off the field and has a proven track record of playmaking that will benefit the entire defensive unit," new Dolphins general manager Dennis Hickey said of Delmas.
Patterson's release offers Miami more flexibility. The Dolphins could use it after recently signing cornerback Brent Grimes to a four-year, $32 million contract last week.
Miami enters free agency with more than $30 million in cap room and is expected to be a major player in free agency for the second year in a row.
ESPN.com Lions reporter Michael Rothstein contributed to this report.