Manchester City midfielder Ilkay Gundogan has described the 'loneliness' and the feeling of being 'useless' during the long months he spent on the sidelines while he nursed a knee ligament injury, watching on as his team-mates continued without him.

Gundogan damaged the anterior curciate ligament in his right knee beyond repair during a Premier League game against Watford in December, nine long months ago.

Manchester City v Watford - Premier League

His 'completely torn' ACL was replaced by part of a tendon taken from his patella under the knife of renowned specialist Dr Ramon Cugat in Barcelona. Then it was all about rehab and the long road back to fitness for Gundogan.

"The general feeling is of loneliness," the popular 26-year-old explained in an in-depth interview with the New York Times"The worst thing for me is seeing the other players.

"I see them on the training field, when they are in the locker room, when they go up to the meeting before training. I see how they work in the gym, and I am not able to do the same. You know that you are not able to be a full part of the group.

"That is the most difficult thing: to feel that you are useless, not worth as much as before, not worth as much as the others."

Gundogan, who missed virtually all of the 2013/14 campaign for Borussia Dortmund because of injury and has never managed more than 28 league games in a single season in his career to date, finally returned to the pitch last weekend.

Manchester City v Arsenal  - Premier League

Ironically, it was another game against Watford, seeing the German come full circle.

Gundogan played again against West Brom in the Carabao Cup on Wednesday night, but City fans and staff will now be holding their breath after he seemed to suffer another injury.

"I think it's not serious, it's not eight months, but a little injury. Unfortunately the action is tough. He will be back soon hopefully," manager Pep Guardiola said after the game.