By Dominic Toner

Arsenal defender Per Mertesacker could be sidelined for up to five months with a knee injury, according to a reliable journalist.

Kike Marin, a senior correspondent and columnist for Spain’s leading online newspaper El Confidencial, revealed on his personal Twitter account on Monday night the German defender is facing a lengthy absence in what would be a shattering blow for the Gunners.

Arsenal announced on their official Twitter account on Monday that Mertesacker had sustained a knee problem and would not be a part of the squad that travels on their pre-season tour of the USA, meaning he could be in danger of missing the season opener against Liverpool.

The Londoners did not disclose any further details about the extent of the Mertesacker injury but Marin has claimed that the 31-year-old is facing an extended spell out.

The potential long-term absence of the former Germany international would be a shattering blow for Arsene Wenger.

Mertesacker was lined up to be appointed the new captain this season and remains a first-team regular even though he has entered the final year of his contract.

The former Germany international was pushed closely by Brazilian Gabriel Paulista in the battle to partner Laurent Koscielny at the heart of the defence last season but ended the campaign in the team.

The 2014 World Cup winner has made 207 appearances in all competitions since joining Arsenal in 2011 and his experience will be sorely missed.

Tribal football claim that Arsenal are interested in Inter Milan centre-back Jeison Murillo after he excelled in Colombia’s Copa America campaign, and he could be another possible player to fill in for Mertesacker.

The opening Premier League match against rivals Liverpool will be made even harder as five other senior stars are set to miss the clash, with Alexis Sanchez struggling with an injury according to the Mail Online.

In other Arsenal team news, a number of senior Gunners players are in doubt for the start of the upcoming campaign.