Barcelona legend Hristo Stoichkov has tipped Real Madrid to sell Cristiano Ronaldo to Manchester United if the price is right and claimed the world player of the year is tired of ‘only’ being compared with Lionel Messi. The former striker was speaking in a Sportium promotion when he was asked about Ronaldo and he said: ‘You would have to ask Florentino [Perez] about Ronaldo’s future. Sooner or later he will be sold by the president. ‘Football is like that but it depends on the president. I don’t know if he needs the money; if he does then it is a good moment to sell him.’ Hristo Stoichkov has claimed it would be a good time for Real Madrid to sell Cristiano Ronaldo . The former Barcelona and Bulgaria striker tipped Ronaldo to return to Manchester United . Stoichkov celebrates scoring for Bulgaria against Spain during Euro 96 in England . Stoichkov also claimed part of Ronaldo’s recent unhapiness stems from being tired of comparisons with Messi. He said: ‘You can’t doubt the quality of either one of them. Messi is where he should be but Ronaldo is in a delicate moment. ‘All players go through bad moments, it happened to me too. Perhaps the obsession with Messi affects him. The difference between Ronaldo and Messi is he [Messi] gets compared with Pele, [Diego] Maradona and [Johan] Cruyff and Ronaldo only gets compared with Messi.’ Legendary Barca striker Stoichkov said he believed the BBC at Real Madrid - Gareth Bale Karim Benzema and Ronaldo - are not at the same level as Messi, Neymar and Luis Suarez. Stoichkov (right) is a legend at Real's rivals Barcelona, whom he helped to the 1992 European Cup (pictured) It has been rumoured that Ronaldo is unsettled at Real Madrid and may leave in the summer . Stoichkov suggested Ronaldo is tired of constant comparisons with Barcelona star Lionel Messi (above) ‘They are low on morale,’ he said. ‘Between the two forward lines Barca’s is better at the moment and you always have to look to see if the players are enjoying themselves or not.’ Asked if he could see himself in Barca forward Suarez, Stoichkov said: ‘He came with the label of problem player after the World Cup but I am convinced he will help them try to win the three competitions they are competing in.’
Manchester United could make a move for Cristiano Ronaldo this summer . Hristo Stoichkov says Real Madrid should sell Ronaldo . Ex-Barcelona striker claims Ronaldo is tired of contest with Lionel Messi . Bulgarian suggested now would be prudent time to sell Portuguese star . He added that trio of Ronaldo, Gareth Bale and Karim Benzema are not as good as Barcelona's Messi, Neymar and Luis Suarez . READ: Ronaldo could return to Manchester United .