Vanderlei Fernandes Silva, simply known as Derlei or Ninja (born July 14, 1975) is a Brazilian football player.

He was born in São Bernardo do Campo, Brazil and currently plays for FC Porto, whom he joined in the summer of 2002 from UD Leiria.

He scored twice for FC Porto in the 2003 UEFA Cup Final.

In January 2004 after disciplinary problems related to his lateness in arriving from the winter break, he was sold to Dynamo Moscow for 7 million euros.