From the CSI Files Article:
Cibrian's character is an as-yet-unnamed officer from the Hollywood division of the Los Angeles Police Department who transfers to the Miami-Dade Police Department. According to Miami's producers, Cibrian will not be replacing Adam Rodriguez's character Eric Delko, who went missing in the season seven finale, "Seeing Red". The premiere of season eight will air Monday, September 21 at 10:00pm ET/PT.
As CSI Files previously reported, Megalyn Echikunwoke( Dr Tara Price)'s departure from Miami during the penultimate episode of season seven ("Dissolved") leaves her character's fate up in the air. While it is not known whether Echikunwoke will be back, it seems that her predecessor, Khandi Alexander (Dr Alexx Woods), is not scheduled to return to the morgue any time soon. Alexander will be one of the main characters on Treme, the upcoming HBO series about post-Katrina New Orleans.