Alves underwent a medical as the Teessiders attempted to push through a club record signing.
The 26-year-old Heerenveen striker is understood to have arrived on Teesside as the two clubs worked to finalise a move which will cost Boro significantly more than the £8.15million they paid Empoli for Massimo Maccarone during the summer of 2002.
However, while agreement is close, there are still details to thrash out before the Brazilian's work permit appeal is heard today.
After seeing his side beat Wigan 1-0, Southgate said: "He is keen to come.
"He is a player we feel can give us and the town a real lift and give us competition for places in those striking positions."