Chelsea and England captain John Terry says Manchester United's Rio Ferdinand must be careful about his recovery from a spate of injuries.
Terry said: "This is the first season for about five, six or seven years that Rio's picked up this many injuries and missed so many games.
"After the two years I had previously with injuries, I've had a great year. As we get a bit older, you need to do those extra bits of work as well to make sure we stay fit.
"It's difficult as a centre-half as well as you throw yourself into a lot more situations where you can pick up injuries. It's taken its toll as well, over the years.
"If you're a midfielder or a striker, you maybe don't need to put your body on the line as much, throwing yourself in front of someone's foot.
"You take so many knocks over the course of a year, you try and shrug it off.
"But, as a centre-half in this country dealing with so many different types of strikers and different situations, you have to put your body on the line."