Midfielder Stuart O'Keefe has confirmed that he felt fine after coming through 45 minutes for Southend United's reserve side on Tuesday.
The 18-year-old played the first half of United's 4-0 defeat against the Cobblers following six weeks out of action.
O'Keefe had a hernia operation in February to cure a troublesome groin problem.
And the product of Blues youth system admitted he felt fine on his comeback appearance.
"I felt really good and fit," he confirmed. "As the first half went on it got a little bit stiff but the medical staff said that was to be expected.
"The result from the match was disappointing but for me it was more important to start to get match fit again."
The Diss born youngsters injury problems struck at the end of January following a substitute appearance against Millwall.
O'Keefe was expecting to be involved versus Swindon Town four days later but took the decision to go under the knife now rather than put it off until the summer.
"I came on against Millwall and I felt I did well," O'Keefe said. "I might have been involved against Swindon also but I couldn't because the pain got to me.
"It was a big decision to have it done now as the surgeons said I could have waited until the summer but I wanted to get it out of the way so I could concentrate on playing."
Ironically for the first year pro his absence from action couldn't have come at a worst time.
O'Keefe had been missing throughout a period when Blues were without first choice centre midfielders Jean-Francois Christophe, Alan McCormack or Anthony Grant.
And it is only now that they are all beginning to return to action, as O'Keefe looks to regain his own fitness.
"Alan McCormack has been suspended and Anthony Grant injured also so I was upset that I could have had a run in the team," Stuart admitted. "But there was no point in rushing back as this is an important time in my development.
"I've the rest of this season to get myself back fit and then next year is a big year for me.
"It's difficult training all week and I want to contribute to the team. I've not had that chance yet which is frustrating but I'll keep grafting and be ready when needed.
"We've good enough personnel to stay up this season but it's hard with not winning at the moment.
"On Saturday we've got Carlisle who could have one eye on their cup final at Wembley so hopefully that can work in our favour."
