Arsenal agree deal for Celtic left-back Kieran Tierney, closing in on Chelsea defender David Luiz, say reports

Arsenal could bolster their defence significantly in the final 24 hours before the Premier League transfer window closes on Thursday with the signings of Kieran Tierney and David Luiz, according to reports.

Scottish left-back Tierney has been a target all summer for the Gunners, who have had two bids previously rejected by Celtic.

However, Tierney, who sat out Celtic's 1-1 draw with CFR Cluj in Romania on Wednesday as he recovers from a hernia operation, is set to travel to London after the clubs finally agreed on the payment structure of a £25 million move according to widespread reports.

"I've said the last few days it wouldn't surprise me," Celtic boss Neil Lennon told the BBC on the possibility of losing Tierney.

"If he goes, he goes with everyone's best wishes. He's an outstanding talent and a great kid."

Arsenal's long search for centre-back cover could also be resolved on Thursday should Luiz move across London from Chelsea.

The 32-year-old did not train with the rest of his Chelsea teammates on Wednesday.

"If we can on the last day, we will try to sign another centre-back, but one who has the capacity to help us," said Arsenal coach Unai Emery.

Arsenal conceded 51 goals in the Premier League last season to miss out on Champions League football for a third consecutive season.

And their defence was further weakened by the departure of club captain Laurent Koscielny to Bordeaux on Tuesday.