Manchester City midfielder Ilkay Gundogan is afraid he will never regain his best form following his latest injury nightmare.

The Germany international made his first appearance of the season as a second-half substitute in the 6-0 win at Watford last Saturday and is in line to start Wednesday's EFL Cup match against West Brom.

It was Gundogan's first game since he suffered cruciate ligament damage last December, an injury that struck following a strong start to his City career following his move from Borussia Dortmund.

The 26-year-old missed the majority of the 2013-14 campaign with a back injury that kept him out of Germany's triumphant World Cup campaign, and knee damage picked up in Dortmund training in May last year saw him miss Euro 2016.

Gundogan admits there is a heavy psychological toll from such long-term problems and concedes he is not the same player he was prior to December 14 last year.

"It was a long wait – and tough as well," he said. "That is why it feels so special to return. I was sad just to watch in front of the TV or in the stands.

"To be honest, you don't feel as part of the group anymore. You are not travelling with the team anymore. You do everything on your own or with the physio. So of course, that is the worst feeling you can have as a football player. So, that is also the reason it was that hard over the months.

"The worst time was of course the day of the injury or when I knew what exactly happened. When I knew there would be six, seven, eight, nine months out. That was the worst feeling. 

"The day after the surgery was not so good either. But then, at one point, you start to do it again. You start to do your rehabilitation. You recover. You have ups and downs, days you feel better, days you feel very bad. I think that is normal. It is not just me.

"There are doubts if I will be again at the level I had before so, of course that is the case. As I said because of these ups and downs, more of the downs, it is sometimes frustrating. The doubts are at this point even bigger.

"But I had no other choice. I am a football player. This is what I do. This is what I have done all my life. This is my job. For me, there was no other choice than to try again.

"If I said I am the same player as I was a year ago, I would be lying. I mean, through the injury, you don't feel the same. You don't feel as though you are the most powerful guy in the world – not that I ever did. I had two injuries on my knee and I know what to do to prepare myself for the games and to warm my knee up and be generally fit. 

"I will do everything to be as fit as possible. That could be it for all the injuries! I think I am done now! I am ready to continue playing, to keep fit. To enjoy playing."