Kylian Mbappe has insisted he trusts Paul Pogba's word after the Paris Saint-Germain attacker's name was dragged into a blackmail affair currently engulfing his France teammate. Last week, Pogba's brother Mathias used social media to publish what he described as “great revelations” about his younger sibling. Among other claims, Mathias alleged Paul had asked a witch doctor to cast a spell on Mbappe. Pogba, who left Manchester United in the close season and <a href="https://www.thenationalnews.com/sport/football/2022/07/11/paul-pogba-completes-move-back-to-juventus-on-a-free-transfer/" target="_blank">returned to former club Juventus on a free transfer</a>, denies the accusation. His lawyers issued a statement in response to Mathias' claims, saying the comments had followed “threats and attempts of extortion by an organised gang”. A criminal investigation was launched in France last week into the affair. Based on the findings of a preliminary investigation last month it will examine allegations – for now against persons unknown – including blackmail by an armed gang, kidnapping and membership of a criminal conspiracy. Mbappe and Pogba played key roles in France's 2018 World Cup victory in Russia and hope to play a part in defending the trophy in Qatar later this year. “No because today as things stand I prefer to believe what my teammate says,” PSG star Mbappe said when asked if there might be a problem with Pogba. “He called me and gave me his version of events. Right now, it is his word against his brother's word. I am going to trust my teammate. “I think it's in the interests of the national team as well with a big tournament coming up. “At the moment, he already has certain problems and now is not the time to add to those problems. “We'll see what happens but I am quite detached from all that.” Meanwhile, reports also emerged on Monday that Pogba will have to undergo knee surgery, putting his participation in November’s World Cup in doubt. The 29-year-old <a href="https://www.thenationalnews.com/sport/football/2022/07/26/injury-blow-for-juventus-with-paul-pogba-set-for-spell-on-sidelines-due-to-knee-problem/" target="_blank">injured the meniscus of his right knee in July</a>, forcing him to miss the second leg of the club's preseason tour of the US. He had decided against surgery in a bid to make sure he would be fit for Qatar. According to <i>The Athletic</i>, Pogba was back running on a treadmill on Sunday and was then at Juventus’ Continassa training ground for a test 24 hours later. Pogba, though, felt discomfort during the examination and has now decided to go under the knife. Juventus manager Massimiliano Allegri said on Monday: “I have to count on having him back in January. Whether he plays the <a href="https://theathletic.com/football/world-cup/">World Cup</a> or not isn’t my problem.”