Arsenal have already conceded 26 goals in 21 Premier League fixtures and the Gunners really need to strengthen the back line in the winter transfer widow.As far as the central defense issue is concerned, Laurent Koscielny and Shkodran Mustafi are Arsene Wenger's first choice but the pair have been inconsistent this season.In such a scenario, new reports suggest that the FA Cup holders are looking to sign Chelsea out-of-favour star David Luiz to reinforce their defense.According to an exclusive report covered by the Daily Express, the North London club are favourites to sign the Brazil international, who has not featured for Antonio Conte's side since October last year.At first, the ex-Paris Saint-Germain star was relegated from the starting...
