The Football Association has sought observations from Wayne Rooney in relation to comments by the Derby County manager in a recent interview.

Rooney said he changed his studs to "long metal ones" when playing for Manchester United at Chelsea in 2006 as he "wanted to try and hurt someone".

United were beaten 3-0 and Chelsea won the top-flight the title that season.

"We knew if Chelsea won then they had won the league that day," said 36-year-old Rooney.

"Until my last game for Derby, I always wore the old plastic studs with the metal tip.

"For that game I changed them to big, long metal ones - the maximum length you could have because I wanted to try and hurt someone, try and injure someone.

"I knew they were going to win that game. You could feel they were a better team at the time so I changed my studs.

"The studs were legal but thinking if there's a challenge there I knew I'd want to go in for it properly, basically. I did actually.

"John Terry left the stadium on crutches. I left a hole in his foot and then I signed my shirt to him after the game... and a few weeks later I sent it to him and asked for my stud back.

"If you look back when they were celebrating, JT's got his crutches from that tackle."