He said: "The Barcelona game is 50-50 - it is anyone's. You have two great teams both capable of going and winning it.
"Having the distance between winning the first and second Champions League has made people like myself more determined to retain it. You appreciate the opportunity you have because you know they do not come around too often.
"Those of us who have been there before have been able to tell the other lads 'listen, this doesn't happen every season'.
"I had to wait nine years for my second. When you have won it you have to try and make it carry on, we want to be the first team to defend it.
"I thought about that more or less after last year's final.
"It is those sort of challenges that keep you going, you have got to look for challenges."