Barcelona want to capitalise on the uncertainty at Chelsea by signing César Azpilicueta, Andreas Christensen and Antonio Rüdiger this summer. The La Liga club are rebuilding their squad amid a financially turbulent period and are aiming to strengthen their defence. Christensen is expected to move to the Camp Nou when his contract expires at the end of the season and it has now emerged that Barça, who remain interested in Azpilicueta despite a 12-month extension to his deal being triggered this week, have opened talks with Rüdiger’s representatives about signing the defender on a free. Their moves come at a time when Chelsea are unable to offer players new contracts while they wait for Roman Abramovich to sell the club. Chelsea were granted a licence to continue after sanctions were imposed on Abramovich and will be able to hand out new deals only after the club are sold, with a takeover not expected until at least the end of April. Chelsea have some leverage with Azpilicueta, whose clause was agreed before the sanctions came into effect, but Barça are still in for the Spain international. They have offered the Chelsea captain a two-year contract with the option for an extra year and could pay a small fee for the 32-year-old, who is interested in returning to Spain after 10 years in England. Christensen’s situation is thought to be more straightforward, with the Denmark international almost certain to leave after talks over a new deal broke down. However Rüdiger’s situation is less clear. He has made no decision over his future and could stay if Chelsea’s ownership issues are resolved soon. Rüdiger, who wants about £200,000 a week and a large signing-on fee, has been free to talk to foreign clubs since January and there has been no shortage of interest. Real Madrid, Paris Saint-Germain and Juventus have been linked and eyebrows were raised when pictures emerged of Rüdiger’s brother and agent, Sahr Senesie, entering a hotel in Barcelona with Barça’s director of football, Mateu Alemany, and technical director, Jordi Cruyff. The situation will concern Thomas Tuchel, who is likely to need at least one new centre-back. Chelsea have been tracking Sevilla’s Jules Koundé for a while and have been linked with Juventus’s Matthijs de Ligt. The race to buy Chelsea remains intense and there was another twist this week after it emerged that rival bidders are angry at what they see as preferential treatment being shown towards the Ricketts family by the club. The Ricketts, one of four shortlisted groups preparing to submit offers to buy the club before the 11 April deadline, have faced major opposition from Chelsea fans. A #notoricketts campaign erupted on social media in response to historical Islamophobic remarks made by the family’s patriarch, Joe Ricketts, who is not part of the bid. Comments attributed to other family members have also caused concern. There have been calls for supporters to protest at Stamford Bridge when Chelsea host Brentford on Saturday. One online group is looking to arrange a protest at Stamford Gate at midday, and there have been calls for supporters to display anti-Ricketts banners inside the ground. The outcry led to Tom Ricketts, who is fronting the bid, meeting Paul Canoville, Chelsea’s first black player, in an attempt to improve relations with supporters. However there was controversy after it emerged that Chelsea’s chairman, Bruce Buck, was at the meeting at Stamford Bridge last week. Rival bidders have questioned why Raine, the US bank handling the sale, facilitated the meeting given that prospective buyers are not supposed to be in contact with Chelsea’s executives yet. Buck, who will have a say in picking the preferred bidder, which will be presented to the UK government for approval, insists he did not breach any rules or undermine the integrity of the sale. Chelsea say he played no active role in the meeting. Rival bidders are worried that the Ricketts, who own the Chicago Cubs baseball team and have partnered with the billionaire hedge fund manager Ken Griffin, could receive favourable treatment because they have a business relationship with Raine. Tom Ricketts, Cubs executives and Raine formed a special purpose acquisition company in 2020. The other groups hoping to buy Chelsea are a consortium fronted by Todd Boehly, Hansjörg Wyss and Jonathan Goldstein; the Boston Celtics co-owner Stephen Pagliuca; and a group headed by Sir Martin Broughton and Lord Coe.