Barcelona joined rivals Real Madrid  chasing  Arsenal Defender Keiran Tierney 

Barcelona and Real Madrid could battle it out for Arsenal's Scottish international defender Kieran Tierney this summer Mercato. The 24-year-old defender has impressed Real’s scouts when they were initially sent over to check on Bukayo Saka, while Barcelona are also interested in the player. The Sun reports that a £50 million offer could be made, and Arsenal would be willing to do a deal at the right price.
Ancelotti reportedly tried to sign Tierney in 2019, when he was in charge of Napoli coaching, but eventually decided to sign for Arsenal, arriving from Celtic. However, Football London reports that Ancelotti is expected to try again for Tierney this summer, but will have to fend off competition from Xavi.
Barcelona is expected to make a bid of 50 million pounds that will come from the Spanish capital, Terni, and the Catalan club will also have to comply with La Liga, which is already concerned about Barcelona's financial situation. 
Tierney, the left-back has made 87 appearances across all competitions for the side since his arrival at the Emirates, scoring four goals and providing 12 assists in the process.