Manchester United boss Jose Mourinho can appear to seek "war not football" during difficult periods, Barcelona legend Xavi has said in the Daily Mirror.

However, Xavi, who played for Barca during Mourinho's three-year reign at Real Madrid, said the Portuguese remains one of the finest coaches in the game and that his renewed rivalry with Pep Guardiola "can be the best in football."

The enmity between Barca and Madrid escalated during Mourinho's time at the Bernabeu and, speaking ahead of Wednesday's Manchester derby in the EFL Cup, Xavi said: "Sometimes, when things don't go well for Mourinho, he wants war not football -- like when he was at Madrid -- and I hope we don't see that again in England."

Xavi has already backed his former Barca boss Guardiola to change English football in his role as Manchester City boss and the 36-year-old midfielder, currently playing for Qatari club Al Sadd, said his battle with Mourinho is an added bonus for the country.

"When I knew they would be rival coaches again, I knew it would be good for football," Xavi said. "I knew it would be especially good for English football. They're two of the best coaches in the world and their duel can be the best in football."