Newcastle manager Bobby Robson has confirmed the club have launched a double bid to sign Jonathan Woodgate and Kleberson.
Newcastle have contacted Leeds United and Brazilian side Atletico Paranaense to make initial inquiries over the two players.
"All I can confirm to you now is that the club have actually made communication to both clubs in respect of the two players concerned," he said.
"There's a lot of communication and dialogue will have to go on before anything happens in that respect, but all we've done is made preliminary investigations into those two players.