I was a versatile player, known for my work rate and tactical intelligence, and won the Champions League with Liverpool. I had a spell in Italy before joining the Reds and also represented my country in multiple major tournaments. Who am I?

1. I joined Liverpool from an Italian club.
2. I was a key part of Liverpool's midfield in the 2000s.
3. I won the Champions League in 2005.
4. My primary position was midfield, but I was often deployed in defense as well.