Everton defender Phil Jagielka could miss up to nine weeks with medial knee ligament damage, Toffees manager Roberto Martinez has confirmed.

England international Jagielka, 33, picked up the injury in the 2-1 loss at Arsenal on Saturday and although Martinez was pleased his knee cartilage and cruciate ligament remain unaffected, the Spaniard could be without his centre-back for the next two months.

"I wouldn't expect anything longer than eight to nine weeks," Martinez said when asked about the defender's recovery timetable.

The injury will ensure England manager Roy Hodgson is unable to select Jagielka for the November friendlies with Spain and France while the defender's club side could be without their skipper for the remainder of the calendar year.

However, Martinez was upbeat about the severity of the problem amid initial concerns Jagielka could have been out for an even longer period of time following the challenge from his international colleague Alex Oxlade-Chamberlain.

"After the game we expected the worse, especially in the way that the injury happened and rotating that knee – it could have been anything," Martinez added.

"We had the scan and his medial ligament is affected, it's an injury that is quite straightforward from that point of view, but there is no other damage in the knee. The meniscus, the cartilage and the cruciates are very, very strong. It's the least (damage) that it could be."

Jagielka and striker Romelu Lukaku are the only players to have started every game in all competitions this season, but the former will need to replaced in the line-up for Norwich's visit to Goodison Park in the Capital One Cup on Tuesday.

Martinez confirmed Joel Robles will start in goal in place of Tim Howard, as he did in the last round, while Gareth Barry's late dismissal against the Gunners rules him out through suspension – meaning three of the squad's most experienced members will not play on Tuesday.

"It's a huge miss," Martinez said of Jagielka's absence.

"This campaign we've had to cope with many injuries already, especially in the back four. You rely on certain leaders to allow young players to come in and be able to perform. Phil Jagielka's role in that has been immense and probably that's what will be missed.

"You don't want to lose your captain, you don't want to lose an influential player, but that happens in a season – you get injuries, you get suspensions and you have to cope with that.

"As a team we've got other senior players who can take over that role and that influence and that's what we need to show on Tuesday."

Jagielka's injury will likely open the door for Ramiro Funes Mori to partner John Stones at the heart of defense for an extended period, with the Argentinian having made just two starts since joining from River Plate this summer.

Martinez is confident the 24-year-old can grasp the opportunity Jagielka's injury has presented him.

"He's had a good period now to settle in, to understand the team-mates, the way we want to play and the league itself," Martinez said.

"I thought he was so impressive in all the roles he had to take from playing in the League Cup, from having to perform in a Merseyside derby, from having to come on in a difficult moment against the league leaders. I've been very, very impressed with him.

"I think he's ready. He's someone with an incredible, brave attitude – very commanding."