By London correspondent Tony Hughes

Arsene Wenger wants to sign a new defender by Friday of this week in response to Arsenal’s injury crisis at the back.

The Mirror claim the Gunners manager is trying to secure either Valencia’s Shkodran Mustafi or Jonny Evans of West Brom before the Premier League opener at home to Liverpool on Sunday.

It is said Arsenal may try to imminently land both their centre-back targets if crocked Gabriel is ruled out for a lengthy period with the ankle injury he suffered on Sunday.

The Gunners fear the Brazilian could join fellow centre-back Per Mertesacker on the long-term injured list after he was injured in the 3-2 pre-season friendly win against Manchester City.

Gabriel was reduced to tears and left the Ullevi Stadium with his left foot in a protective boot after suffering suspected ankle ligament damage.

Arsenal will assess the Brazilian further on Tuesday but he is certain to miss Liverpool’s visit to north London, and concerns he faces a lengthy spell on the ­sidelines have increased the club’s already pressing need to bring in defensive reinforcements.

Wenger has admitted that he is scouring the market for a new centre-back, although midfielder enforcer Francis Coquelin is being considered as a stop-gap option in addition to rookie pair Calum Chambers and Rob Holding.

The Mirror claim the Gunners would not expect to pay much more than £25million for Mustafi even though he has a release clause of £42million. It is reported that  Manchester United old boy and Northern Ireland international Evans, 28, is valued at around £15million.

Germany international Mustafi has won 12 caps for his country after establishing himself as a regular for his La Liga side since his transfer from Sampdoria in 2014.

The former Everton academy graduate featured for the World Cup winners at Euro 2016 and scored in the opening match against Ukraine, which his team won 2-0.

Mustafi has three years left on his current deal in Germany but could be tempted by a move to the Premier League.

In other Arsenal transfer news, manager Arsene Wenger has lined up this ex-Manchester United fan favourite.