Arsenal transfer news: Gunners end summer window with a flourish after signing Kieran Tierney and David Luiz

Having left it to the final day of the window, Arsenal now head into the new season with a combination of defensive youth and experience to hand

Arsenal ended the summer transfer window with a double swoop as they added Celtic’s Kieran Tierney and Chelsea’s David Luiz to their ranks.

Following lengthy discussions with the Scottish champions, which dragged on for much of the summer, Arsenal finally settled upon a £25m deal for Tierney while Luiz is understood to have cost £8m after pushing for a late exit from Stamford Bridge on Wednesday.

Despite bolstering their frontline options through the signing of Nicolas Pepe, there were fears the Gunners would be left vulnerable at the back following the departure of captain Laurent Koscielny to Bordeaux.

But, having left it to the final day of the window, Arsenal now head into the new season with a combination of defensive youth and experience to hand.

Of his move to Arsenal, Tierney, 22, said he felt he had to take a step forward in his career after living his dream at Parkhead.

Celtic insisted they did everything possible to keep the left-back before selling him for a record Scottish transfer fee.

The youngster had been at his boyhood heroes from the age of seven and was under contract until 2023 but, after making 170 first-team appearances and winning 10 trophies, his ambitions changed.

Tierney said: “It was the hardest decision in my whole life that I’ve had to make.

“I had to speak to my family and my close friends and my agent as well because it’s a hard decision to leave a club that you love so much. People need to know that as well.

“I feel Arsenal is a massive club and it’s a great opportunity for me as well. I’m delighted to be here.

“When I was younger, it was always Celtic. The ambition was Celtic and that was my dream when I was younger. But when you get older... I’ve done that, I’ve made my dream, I’ve lived my dream and I’ve loved every single minute of it.

“Now I just feel was the right time to take a step on. I feel this is a great opportunity for me.”

Luiz, meanwhile, joins after an apparent break down in relations with Frank Lampard. It’s believed the Brazilian had fallen behind Andreas Christiansen and Kurt Zouma in the club’s pecking order and was wary of a lack of playing time under the new manager.

The 32-year-old, who first moved to Stamford Bridge in 2011 before later returning in 2016 after a two-year spell at Paris Saint-Germain, trained separately from his Chelsea teammates on Wednesday in an attempt to force through a switch to Arsenal.

Chelsea were happy to sanction the £8m move, The Independent understands.

Unai Emery, who worked with Luiz at PSG, said his experience can help strengthen Arsenal’s troublesome defence. “David has huge experience and I look forward to working with him again,” he said. “He is a well known player and adds to our defensive strength.”

Tierney and Luiz are Arsenal’s fourth and fifth signings of the summer respectively. They follow Daniel Ceballos, on loan from Real Madrid, William Saliba and Pepe, the latter costing a club record £72m.