Monaco have joined Barcelona in their interest of signing Valencia defender Jeremy Mathieu.A number of European teams sent scouts to watch Valencia v Dynamo Kiev in the Europa League on Thursday night and [FDN] learnt that La Liga giants Barcelona were in attendance to cast a closer eye over French centre-back Mathieu.googletag.cmd.push(function() { googletag.display(“div-gpt-ad-1389116196215-0”); });However, according to Le10sport, Monaco are also interested and were impressed with his performance in the Europa League.The Ligue 1 side are keen to partner Mathieu with fellow French international Eric Abidal next season as they seek to push Paris Saint Germain for the title.Mathieu is capable of playing at left-back but has started in 26 out of his 27 games at centre-back for Los Che.