Dani Alves, a former defender for Barcelona, referred to Manchester United forward Cristiano Ronaldo as "a b*stard" while acknowledging that the 37-year-old is the most challenging opponent he has ever faced.

While playing for Real Madrid, Ronaldo won the Champions League four times, but only twice in La Liga.

During Ronaldo's time in Madrid, Barcelona dominated the domestic scene and won the championship six times.

Alves was one of the regulars in the Barcelona side that enjoyed that sustained period of success, with the veteran widely considered one of the club’s finest full-backs of all time.

But according to the UK Mirror, Alves had no hesitation in naming Ronaldo as his toughest opponent.

“Cristiano Ronaldo." This b****** doesn’t let you breathe for a second.

“I didn’t do too badly, but it’s difficult." "He's a scoring machine,” Alves said.