Manchester City star Vincent Kompany admits the level of depth at Manchester City was not normal.
While Kompany was plagued by injury issues during his last few years at the club, there were always capable replacements when he went down.
The likes of Nicolas Otamendi, John Stones and Aymeric Laporte all competed for a starting spot, along with Kompany.
Kompany said to reporters: "Three world-class centre backs is awesome by any standard. In the past we had the luxury of four but I've not seen many teams have four top, top centre-backs.
"It wasn't normal. It only happened because of circumstance. 'OK, Vinny could break down, so we'll bring in another one'.
"Most clubs aren't advised to do it and have three. Most clubs run with three world-class centre backs and a young one. City have got unlucky with an injury, that's it."