Chelsea are reportedly confident of completing the deal for Brazilian youngster Nathan despite a late approach from Portuguese club Porto to take the youngster to the Estadio do Dragao.

According to the Daily Mail, the player has completed his medical and agreed personal terms with the west London club ahead of a summer move.

Nathan, who plays for Atletico Paranaense in Brazil, was at the Emirates Stadium for the Blues' clash against Arsenal in the Premier League and the player has himself tweeted that he is at Stamford Bridge to sign the contract and undergo a medical.

"Very happy!!! In London to sign my contract with Chelsea and take tests", he tweeted, as quoted by the Daily Mail.

According to the player's social networking account, he has been to the training ground and met up with the other Blues stars and has admitted that it will be an honour to play alongside them.

"Hazard, Oscar, William and all very humble team, received me very well. It will be an honor to play alongside these superstars," the young Brazil U20 international added.

The 19-year-old attacking midfielder, who can also play as a second striker or as a left-winger, came to the fore during the Fifa U17 World Cup, where he scored five goals and his all round performances for the Selecao caught the eye of the Premier League clubs.

Chelsea have reportedly agreed a £4.5m deal with the Brazilian club for the transfer of the midfielder and look to have beaten off competition from Portuguese giants Porto.

However, Jose Mourinho played down the move for the youngster earlier in the month. While he did not deny that Chelsea were after the player, he indicated that he was not working on the transfer.

"I'm not worried about that. I'm not working on that. Not at all," Mourinho said, as quoted by the Independent.