Steve Bruce feels Andy Reid is now fighting fit for Sunderland after watching the slimmed-down midfielder net a brace in the 4-1 Carling Cup win at League One Norwich.
Teemu Tainio set the ball rolling for the Barclays Premier League club after 26 minutes, with Reid chipping in a superb second and making it 3-0 before half-time.
Wes Hoolahan reduced the deficit just after the hour, only for Owain Tudur Jones to deflect a corner into his own net as City finished the match with only nine men after defender Michael Spillane was sent off for a professional foul on Frazier Campbell and keeper Ben Alnwick suffered up a cut to his face.
Dubliner Reid, 27, underwent a rigorous fitness regime in the summer to cut down his notoriously excessive weight.
Bruce maintains that is a credit to the former Tottenham and Charlton man.
"I do not think anyone has questioned his ability, but the one thing which has been levelled at him is his physical condition," said Bruce.
"He has now lost something like nine kilograms, 22 millimetres of body fat, which has taken him down to what you have seen today.
"He has always been blessed with ability, and now has got himself in a condition which you have to be - I think the penny has dropped that you have to be that way to play in the Premier League."
Bruce added: "Fair play to him, he is the one who has done it, I am not going to take any credit for that.
"Over the summer, he has worked hard and watched what he has put in his mouth.
"We all know what to do, but it is very difficult."
Reid - who had netted only two goals since his move from Charlton - was one of nine changes by Bruce for tonight's clash against the team he lifted the Milk Cup with back in 1985.
The Mackems were, though, still far too good for City, whose main concern under new boss Paul Lambert will be getting back into the Coca-Cola Championship at the first attempt.
"We made some changes, and it was good to see the ones who needed a game," said Bruce, who revealed striker Campbell had suffered no worrying injuries from his clash with Alnwick.
"All of the lads have come to the party in some way or another and asked a few questions.
"I can only play 11, but you could see tonight there are five or six knocking on the door, big style."
Sunderland hope to secure the season-long loan signing of Lyon defender John Mensa, and are also closing in on highly-rated 21-year-old Egyptian Ahmed Al-Muhammadi.
"John Mensa is waiting just for his visa to be stamped, and we hope to be able to bring him to the club in the next few days," said Bruce.
Norwich manager Lambert, meanwhile, felt there were some positives to take from the match.
"We started really well, and had some good chances," said the Scot, appointed following the dismissal of Bryan Gunn after just one league game.
"However, when you make individual errors, especially against calibre like that, you will get punished.
"There were some positives to come out of it, and the negatives, well I have already seen them."
Lambert, whose former side Colchester thrashed Norwich 7-1 at Carrow Road on the opening day of the season, added: "It is not about a magic wand, it is to try to get the club up the league.
"I could not play the same team as on a Saturday because the lads who were brilliant could not play two games in three days."
The extent of the injury to Alnwick, meanwhile, will be assessed in the coming days.
"His faces is a bit of a mess at the minute, so we just need to see how it settles down," said Lambert.
"He has got quite a bad gash under his eye, and have to monitor him."