The 30-year-old centre-back said: "I was watching the transfer news up until midnight to see what was going on. It was an amazing day.
"It's like a Roman Abramovich at Chelsea type thing, you know. To come in and break the British transfer record in one day is pretty amazing.
"If they've got that type of wealth and they've got players like Robinho - one of the best players in the world - then it's something you have to think about."