Former Liverpool captain Steven Gerrard has claimed that Rafael Benitez was "stupid" to sell Xabi Alonso to Real Madrid.

The Spanish midfielder played alongside Gerrard for five years, with the pair winning the 2005 Champions League under Benitez, before he left to join Real in 2009.

Gerrard has hinted that Alonso's exit brought about a decline at Anfield.

"It was clear Alonso was royalty after our first training session together in August 2004, and Rafa Benitez, who had been so clever to buy him in the first place, was equally stupid to sell him to Real Madrid five years later. He was, by some distance, the best central midfielder I ever played alongside," Gerrard wrote in his autobiography, as serialised by the Daily Mail.

"It was a disastrous decision to sell Alonso, and especially for just £30m — which looks a snip now when you reflect on all he has achieved subsequently, both at Real Madrid and Bayern Munich and with Spain, winning the Euros and the World Cup.

"I blame Rafa entirely for the loss of Alonso. He could still have been playing for Liverpool six or seven years after he left in 2009."

Gerrard has revealed that he and Benitez had a "distant and emotionless" relationship during their time at Anfield.