Arsene Wenger is facing a mounting injury crisis ahead of the new season with news that Nacho Monreal has joined captain Thomas Vermaelen and Laurent Koscielny on the Arsenal's treatment table.
Much of Arsenal's focus so far during the summer's transfer window has been upon their search for attacking options with the club linked with moves for Liverpool's Luis Suarez and Manchester United's Wayne Rooney.
But the Arsenal boss may have to address a number of growing concerns at the other end of the pitch, as Spain international Monreal joins a lengthening injury list with less than a month to go before the new campaign kicks off.
The Daily Mirror report that the former Malaga full back will miss the start of the new campaign "after damaging a disc in his back," leaving the Arsenal boss with just Kieran Gibbs as his only fit option at left back.
"Monreal has had an injection and it looks like he will miss the start of the season and of course we have lost one left back and that's a position where we are a bit exposed," Wenger is quoted as saying in the Mirror.
"Vermaelen can play there, he is injured. Monreal can play there, he is injured. At the moment we only have Kieran Gibbs who can play at left back."
Wenger has already seen first choice centre half Laurent Koscielny limp out of training encounter in Asia after suffering a suspected ankle injury.
The Gunners are yet to confirm the severity of the Frenchman's injury, but such is the extent of their concerns compatriot Bacary Sagna was forced to fill in at centre half alongside Per Mertesacker during Monday's 3-1 win over Nagoya Grampus Eight.
Club captain Vermaelen will miss the start of the season after suffering a lower back injury that could see him sidelined for three months, leaving Wenger with just Sagna, Mertesacker, Gibbs and Carl Jenkinson as his first team defensive options,
Ignasi Miquel, 20, remains in reserve but after a succession of uncertain displays in the Gunners first team, questions remain over Wenger's willingness to throw the youngster into the fray at such an early stage of the season.
Wenger has already rid his squad of a number of defensive options deemed surplus to requirements, with Sebastien Squillaci released, Johan Djourou sent out on a season long loan to Hamburg and Andre Santos given the green light to return to Brazil so far this summer.
Arsenal begin their season at home to Aston Villa before their two-legged Champions League play-off sandwiches the trip to Fulham.