McCarthy set for Porto
The South African has now agreed a four-year deal with the reigning Uefa Cup holders after his club Celta Vigo agreed a é¼3.3 million (£2.3 million) fee with Porto.
The transfer should be officially sealed early next week and will bring to an end a saga which has lasted several weeks.
Meanwhile, Celta are confident that Russian midfielder Alexander Mostovoi will sign a contract extension with the club once he has returned from his holidays.
The 35-year-old had been stalling on penning a new deal at El Estadio Balaidos, but it now seems the veteran schemer will agree a new one-year deal with the Galician outfit.