Chris Wood forced off vs Porto just a day after revealing he's suffered injury that must be managed for life

A day after Chris Wood revealed that his knee will never completely recover from an injury suffered in October, the striker was forced off against Porto following a painful knock to his right knee.

The New Zealand international, 34, scored 20 Premier League goals for Forest last season to help them qualify for the Europa League.

He started this campaign with an opening-day brace in a 3-1 win over Brentford, but suffered a knee problem shortly before Sean Dyche's arrival as manager in October.

The injury caused Wood to miss five months of action before he made his return in a reserve team match last month.

He had initially hoped to be back much earlier before the decision was taken to undergo surgery in December.

The striker made his first-team comeback by starting Forest's 1-1 draw at FC Porto in the Europa League, before appearing as a second-half substitute in the 1-1 Premier League draw against Aston Villa on Sunday.

Now, speaking in a press conference ahead of the second leg of Forest's quarter-final tie against Porto, Wood has opened up on the exact extent of his knee issues and how it will need to managed for the rest of his life.

"It is a knee injury. It is going to take years of managing throughout my whole career, in my life when I have finished playing," he explained.

"When I am playing with my kids, playing golf or doing whatever I do after, it is going to be there.

"I would not say managing, per se, but it is always going to be in the back of my mind that I need to be in top shape.

"It is going to be a balancing act. I would just say I feel as though I am fully up to fitness, and the only way to get sharp is to get out on the pitch and play games.

"It definitely wasn't a straight-forward injury. We tried a few different avenues to get it right to begin with before going down the surgery route.

"It just didn't work out the way we wanted it to. We had to do what we had to do, and at least we got an outcome at the end of it and a goal to come back to.

"I always had confidence that I'd be back this season. Knee injuries are always horrible. You never know what could happen in the future, or how you're going to come back from it. So mentally, that's one of the tough things to deal with.

"It's one of those things in football where you just have to try and get through it. You have good days and bad days, like anything.

"Some days, it's easy to come in to work and get your rehab done, and do what you need to do. There's other days where you're coming in and you feel like there's no light at the end of the tunnel.

"It's about trying to be resilient, trying to get through it. And that's when you have the help of the medical team, the help of your team-mates around you to keep positive and keep you firing and keep you pushing in the right direction to get it back as fit as possible and as strong as possible for the rest of my career, not only this season."

A day later, in their Europa League quarter-final second leg against Porto, the striker was replaced by Igor Jesus in the 16th minute after Jan Bednarek followed through on Wood's knee with a high challenge.

Bednarek was given a straight red card for the tackle, while Wood could not continue.

As per BBC Nottingham Sport, former Forest defender Brian Laws said of the incident: "That's a career threatening challenge. Absolutely reckless.'

There are countless examples of players who have been able to manage injuries towards the end of their careers.

Ledley King suffered from chronic knee problems after undergoing surgery at the age of 26 in 2007, and was rarely able to train with the rest of the Spurs squad.

The centre-back managed to prolong his career until 2012, but was forced to retire at the age of 31.

Former West Ham, QPR and Brighton forward Bobby Zamora suffered from chronic hip problems from the age of 31, which limited his game time and ability to train.

Zamora scored the winning goal in the 2014 Championship play-off final for QPR and continued playing until he was 35.