Norwich City have made a squeaky clean start to the season on the disciplinary front – but even manager Chris Hughton admits it cannot last.

The Canaries have yet to collect a yellow or red card this season in three Premier League games, plus one Capital One Cup tie.

Much more of this and they will calling them mellow Yellows, in stark contrast to the beginning of last season when they consistently fell foul of referees.

On their return to the top flight in 2011-12, Paul Lambert’s City team picked up two red cards and six bookings in the first five league games.

Midfielder David Fox recorded the fastest booking of last season, taking just 37 seconds on the opening day at Wigan to get his name in the referee’s notebook.

City also conceded a penalty in each of those first five matches.

This time, despite conceding penalties against both Fulham and Queens Park Rangers, nobody has been booked.

There were some impressive statistics flying around in cyberspace yesterday – City are apparently the only team in Europe’s top five leagues yet to receive a single yellow or red card, and only the sixth team to go without either a booking or sending-off in their first three Premier League games.

Include the League Cup tie against Scunthorpe and it’s their best-behaved spell for three years. Their last “clean” four-match sequence had been in August and September 2009 against Hartlepool, Brentford, Walsall and MK Dons.

The statistics also claim, however, that the Canaries have committed 40 fouls up to now. Not surprisingly, Hughton, discussing disciplinary matters at Colney yesterday, was taking a realistic view of his players’ chances of keeping on the right side of the law.

“I don’t know if this is a good thing or a bad thing. This is starting to get a little bit worrying now, I think,” he joked. “It’s a good thing in one sense because we’ve certainly been competitive enough, particularly in the last two games. It’s something you do speak to the players about in pre-season.

“We also have a referee’s visit in pre-season, and of course it’s something that you welcome because further down the line, if players are being sent off or picking up suspensions it’s something you can certainly do without.

“But it’s something that’s coincidental.

“We compete and we compete very well and I suppose on another occasion there might be one or two of those (challenges) that might be quite near the edge that might go the other way.

“I guess it’s something that is a good thing but I’m quite sure it won’t last for too long. Is there a particular reason for it? No it’s just coincidental.”

Goalkeeper John Ruddy, defender Leon Barnett and skipper Grant Holt all picked up red cards last season and served bans as a result, while on-loan defender Kyle Naughton served a one-match suspension for his first five bookings – he accumulated seven in all – but the ban fell conveniently for the home match against Tottenham for which he was, in any case, ineligible.

Match official Chris Foy is the man for the Canaries to keep on the right side of tomorrow, but after handing out 10 bookings in the three Norwich games he refereed in the Premier League last season – as well as three in his last game between Manchester City and Queens Park Rangers – it may be that time is running out for Hughton’s clean machine.

But, however difficult it gets, it seems unlikely City will ever beat their most unwanted record of 10 red cards in one season, 1996-97, when Darren Eadie, Robert Fleck and Danny Mills were each sent off twice.