(CNN) -- England central defender Rio Ferdinand insists there is "no question" that he will be fit for next year's World Cup finals despite fears over his long-term fitness.
The Manchester United star has not played since the 2-0 defeat at Liverpool in October due to a calf injury, which is linked to a previous back problem.
United manager Sir Alex Ferguson has denied that the defender's injury is long-term and believes he will soon be back in action for the defending Premier League champions.
England manager Fabio Capello has insisted that his 23-man World Cup squad will not include anyone who is not fully fit, raising doubts about the 31-year-old's prospects of going to South Africa.
Ferdinand has played only 12 internationals since Capello took over two years ago, but the former West Ham defender insists he will be ready to answer the Italian's call when he names his squad.
"I'm confident I'll be fit. There's no question I'll be ready for next summer," Ferdinand told Press Association Sport.
Ferdinand has been seeing a specialist in London to try and speed up his recovery. No timescale has been set for his return to action but he is confident he will be back soon.
"It's the worst thing for a player to be injured and to be just watching your team, so I've been working hard to get fit," added Ferdinand.
"The treatment on my injury is going well. It's been quite slowly slowly but we're getting there. I can see the light at the end of the tunnel. It's been a tough and long lay-off for me because I have never been injured before."