David Luiz could be on his way to Arsenal, with Chelsea believed to be open to letting him join their London rivals as Unai Emery’s side are also set to seal the £25m signing of the Celtic defender Kieran Tierney on a busy transfer deadline day.

David Luiz signed a new two-year deal in May, having come within weeks of becoming a free agent in what was an unusual step for Chelsea, who have a policy of not offering more than one-year deals to players over 30. Yet with the new head coach, Frank Lampard, offering no guarantees he would be in his first-choice side, it is understood David Luiz asked to leave Stamford Bridge after Arsenal rekindled their interest; they had failed to land him at the end of the January 2018 window.

The Brazilian did not train with the rest of Lampard’s squad on Wednesday , with Chelsea reported to be willing to do business for a cut-price fee of just £8m. .

The London club re-signed David Luiz from Paris Saint-Germain in 2014 for £34m in a deal that was also completed on the final day of the transfer window and it appears likely he could now be on the move again before the market closes for Premier League clubs – something he has made a habit of during his career in Europe. He first signed for Chelsea on the final day of the January 2011 window for £21.5m before being sold to PSG –, where he briefly worked under Emery, for £50m, a world record fee for a defender at the time.

David Luiz, who is represented by Kia Joorabchian, arrived in England after four seasons with Benfica, whom he had joined on loan on the final day of the 2007 January window. In total he has generated an estimated £117m in transfers during 12 years in Europe.

Philippe Coutinho, another Joorabchian client, had also explored the possibility of moving to north London but has rejected Tottenham’s offer to take him on loan.

Meanwhile the left-back Tierney has headed south for contract talks and a medical after weeks of negotiation – including two rejected bids – finally ended with Arsenal agreeing a fee for the 22-year-old. The Scottish champions are also understood to have a sell-on clause and payments based on Champions League qualification as part of the deal.

Barring any late and unforeseen hitches, Tierney is expected to pen a long-term deal worth £75,000 per week. Tierney has proved a revelation since breaking into the first team of his boyhood club, in 2015, with English clubs routinely quoted as keen on his services. “If that is the case, then he goes with everybody’s best wishes,” said Celtic’s manager, Neil Lennon, of the transfer. “He’s a superb player and will be a big loss to us.” News of Tierney’s impending exit broke as Celtic were battling to a 1-1 Champions League qualifying draw in Romania against Cluj. The left-back has missed the opening to Celtic’s season due to injury.

Arsenal’s attempts to sign Dayot Upamecano from RB Leipzig have so far come to nothing after the German club set the France Under-21 international’s asking price at £70m while Juventus have quoted them £50m for Daniele Rugani.