The number 84 is not a particularly common shirt number. No player who is particularly famous has ever worn it.
Meow and meower
Dwight Yorke for Manchester United
Patrick Viera, Cesc Fabregas, Vidic.
Johnny Torres from Wake Forest University.
It is Gary Nevile and and Cafu of Brazil.
Tim Howard for Everton Tiote for Newcastle
Well there is Owen Hargreaves, Cesc Fabregas, and Sergio Ramos!
This number is usually worn by goalkeepers such as Angelo Peruzzi.