Bernard Mensah admits a second knee operation in just over two years left him questioning whether he had a future in professional football but he is back and impressed during his first outing for six months.

Mensah suffered the injury on March 18 whilst on loan at Braintree Town and had surgery later that month on his left knee – the same one which required an operation in December 2011.

The 19-year-old returned during Tuesday’s 1-0 victory over Peterborough United in the Under-21 Premier League Cup and excelled early on. He went close to scoring a hat-trick inside the opening 20 minutes before creating the game’s only goal for Connor Smith midway through the first half (see above for more).

Understandably, his performance and fitness levels deteriorated as the match wore on and he was replaced after an hour.

He spoke to the Watford Observer after the match and admitted his overriding emotion was not one of joy but simply relief.

Mensah said: “The feeling was more relief because I damaged my left knee two years ago and to do it again left me thinking football might not be for me. So I was relieved to be out there after six months of hard work. I’m finally back.”

He continued: “Since I was young I have had a problem with my knee but I think they have corrected it now and there hasn’t been any problems so far. When I did it I thought ‘not again’ but after six months of hard work I’m back and I would say to anyone else in a similar situation to just keep working hard and you will get there.”

Mensah was pleased his family were able to watch his return at Vicarage Road and wanted to thank Watford’s sports therapist Michael Spanou who has assisted the striker throughout his rehabilitation and also attended his operation in March.

The striker signed his first professional contract when he was 16 and penned another deal in January 2013, which will expire in the summer of 2016.

Mensah was grateful for the security provided by the long-term contract during his rehabilitation and believes it helped ensure his future in football was not in doubt.

He said: “When the new owners came in, the club had faith in me and gave me a long contract and I want to thank them for that because if I didn’t have that then I would have been left thinking ‘what should I do next?’ And I might not have been playing football any more.

“But it was good to have that security and now I hope to push on.”

Returning to full fitness is Mensah’s immediate priority and then it will be securing first-team football.

With Troy Deeney, Matej Vydra, Fernando Forestieri, Odion Ighalo and Diego Fabbrini ahead of him in the pecking order at Vicarage Road, Mensah admits that will be difficult at Watford in the short term and he may have to go on loan.

Mensah was handed his first pro deal at a time when the Hornets’ management relied heavily on the academy and its graduates. But Mensah, whose only first-team outing came as a sub against Bolton Wanderers in November 2013, did not bemoan the reduced opportunities, instead saying: “It is a challenge but it is a good one because you are playing with better players and it helps you improve.

“Tonight ten of the starting XI were from the academy and they are all good players. Lloyd Doyley has been here a while, Tommie Hoban is playing in the first team, Connor Smith has played and people like George Byers are coming through so it is not like the club are not producing players.

“We are still producing players and it shows the club still do have faith in the youth players and will chuck them in if needed and it is up to us to show the club we are worth the money they have invested in us via Harefield and the academy.

“A lot of the credit has to go to the academy staff for getting me to this point and the other players here.”

Watford academy’s head of coaching Barry Quin was pleased with Mensah’s impact on Tuesday night after such a long lay-off.

Quin said: “I’ve known Bernard for a few years so I am delighted for him. He was petering out but we planned to give him 60 minutes; he could’ve come off earlier or stayed on a tiny bit longer.

“We don’t want to risk someone but to see him firing for so long and taking a proactive role was really positive.”