David Luiz has been ruled out for up to a month after sustaining a knee injury whilst on international duty with Brazil, according the the defender’s agent.

The centre-back was replaced by Paris Saint-Germain team-mate, Marquinhos, following a challenge from Eduardo Vargas 36 minutes into Brazil’s defeat to Chile on Friday. Luiz has since returned to France and will subsequently endure further medical examinations to decipher the severity of the injury.

The 28-year-old is now expected to be sidelined for domestic encounters with Bastia, Saint-Etienne and Stade Rennais alongside a Champions League double header against Real Madrid.

"The doctor of the Selecao reckons it'll be four weeks before David can return to training." stated the former Chelsea man’s agent, who has given information regarding the player’s fitness in the past. David Luiz’s representative was quick to diminish any worries last season when his client again returned from South America injured, stating it was “nothing serious” and was proved correct despite Luiz missing a trip to Rennes.

The Champions League winner has started six league games for Les Rouge-et-Bleu this season, missing three, with the Parisian outfit sitting comfortably at the summit of Ligue 1 following victory over rivals Marseille prior to the international break.

Kevin Trapp also a worry for Paris Saint-Germain

Luiz will be joined on the sidelines by Kevin Trapp, after the goalkeeper pulled a muscle in his right leg during training on Thursday. The club’s summer addition from Eintracht Frankfurt was subject to two cataclysmic errors against Bordeaux last month but was influential in the aforementioned win at Marseille, saving a last minute penalty. The 26-year-old has been ruled out for six weeks, according to La Parsian, and will surely join his Brazilian counterpart in the stands for the visit of Los Blancos later this month.

David Luiz celebrating with Kevin Trapp after penalty save. (Daily Mail)

David Luiz celebrating with Kevin Trapp after penalty save. (Daily Mail)

Laurent Blanc has opted to use Marquinhos in place of David Luiz when the defender has been unavailable and is likely to partner the youngster with Thiago Silva in the coming weeks. Trapp will be replaced by Salvatore Sirigu as he nurses his injury, showcasing the depth that PSG possess within their squad.