The little Brazilian aims to help Middlesbrough to move up the Premiership table when he arrives from Atletico Madrid on Tuesday. Boro have paid pounds 1.4m to secure the Brazilian's services until the end of the season, when they will have an option to make the move permanent for an additional pounds 6.5m.
Speaking to the Spanish sports newspaper Marca, Juninho said: "I am going with the intention of signing permanently for Middlesbrough. I am leaving many friends here but this group of players is going to win something because of the great dressing-room atmosphere. I am leaving to be a success at Middlesbrough. I will be confident there and that is of great importance to me.
"I was told it would be difficult to play over here [for Atletico] and I need to play when I am not injured. I have had problems in the past and this year I needed confidence to play which is why I am moving. But I cannot remain a player who just makes up numbers in training."
If, as expected, his work permit is granted, Juninho should make his second Middlesbrough debut at home to Southampton on 11 September or in the televised game at Leeds on 19 September.
Juninho, who left the Riverside in 1997, decided to end his time at the Spanish club after finding himself left in the cold by their new coach Claudio Ranieri. Meanwhile, the Brazilian may have to go to an appeals panel for his work permit. A spokesman for the Department for Education and Employment said: "We received the application on 31 August and it will take between 10 days and two weeks to process. At the moment the situation is that we have received it but there has been no decision as yet on whether it has been approved or declined."
While the Juninho situation remains far from clear, there will be no such problem with Senegal-born Ibrahim Ba, the 26-year-old winger who has joined the club from Milan and has a French passport.