Rooney's future at Manchester United remains uncertain, with new Red Devils boss David Moyes expected to address the issue at his first Old Trafford press conference on Friday.
Moyes' predecessor, Sir Alex Ferguson, claimed towards the end of the 2012/13 campaign that Rooney had handed in a transfer request and was looking for a move elsewhere.
Few clubs could match the England international's ambition were he to leave, but Barcelona would certainly fall into that select group.
They have been linked with an approach - despite having already acquired the services of Brazilian superstar Neymar this summer - and Pique feels a man he played alongside during a four-year spell in England would be a welcome addition to the playing ranks at Camp Nou.
He told Sport: "I know he has what's needed to be one of the three best players in the world. He'd fit well with Barcelona.
"He can adapt to many positions. He's best as the centre-forward, but we have seen him on the left or right side.
"He is very versatile, strong, fast and has great technique. I don't think he would have any problems adapting."