Ginaluca Zambrotta is the most versatile defender on the planet and has been for at least 5 or 6 years running. he can play RB/LB which he is the best at without a doubt, or he can play CB if need be.
i dont know if zambrotta could play CB or Cannavaro could play WB
but do the names Maldini and Thuram ring a bell
they both can play RB or LB bc of their experience, and can play CB
and none of u can deny the fact
"In football, the greatest satisfaction is winning when they say you can't." - Robert Paul
Aren't you all forgetting a certain frenchman by the name of William Gallas? This guy is the second best left back in the EPL, and that's not even his prefered role. He is also a very competent center back or right back as well. Also, Toure is extremely versitile in the Arsenal defense.