Norwich City are running out of ways to epitomise their inconsistency.

Their discrepant form has been vastly documented, but the signs of it remain in their play despite David Wagner's best efforts.

Perhaps that's understandable in the context of a side whose confidence has been battered, their reputations damaged and their spirits dampened, but frustrations double when those inconsistencies are borne out in individuals.

For no unit of this City side has that been more true than their defenders.

At one stage skipper Grant Hanley had been one of very few regularly reliable players, as he shook of a first-game red card to dominate opposition attackers.

There was an argument at that juncture that he could have been the Canaries' player of the season, with both Wagner and predecessor Dean Smith pleased with his contribution.

The unique blend of pace and aerial prowess he offered solved numerous problems, and without a real defensive midfielder in place ahead of him.

Fasto forward to City's recent run of good form, and the overall elevation of the players around should have meant a similar upturn for the Scottish international.

Instead, he's been more error-prone than usual, and is beginning to live up to the once-overly harsh criticisms levelled at him externally.

The Pink Un: City skipper Hanley started the season well.City skipper Hanley started the season well. (Image: PA)

In the 3-2 win over Millwall, his calamitous mix-up with defensive partner Ben Gibson was hard to forget even after his offensive team-mates had turned things around. The ensuing backing off as Abdoullah Ba scored Sunderland's winner was surprising from such a commonly proactive protector.

Quite why things have gone awry for the 31-year-old is not clear. Worries surrounding his in-possession strengths faded after an impressive start to life under Wagner, and his starting berth is yet to be relinquished.

The same can be said of Gibson, who appeared to have turned a corner when replacing an injured Andrew Omobamidele.

The former Burnley man had rarely produced under Smith, but looked reinvigorated by a pass that accentuated his long-passing strengths.

Even in adversity he stood up to the pressure, thriving in scenarios requiring last-ditch heading, sliding tackles and battling blocks.

Those qualities were embodied by only one side this weekend, however, and it wasn't the one in yellow and green.

Where Hanley's efforts had lacked proactivity, Gibson's attempt at it should have meant a second goal. Joe Gelhardt's poor finish - stabbed straight at Angus Gunn after the defender had sprung forwards and left a gap to be exploited - was the only thing keeping him from permanent association with a 2-0 loss.

That trademark distribution even struggled when he passed directly out for a corner under no pressure, and it wasn't the first time sympathy's set in for the Middlesbrough-born man.

In spite of the scolding he's felt, however, he's shown previously that he's capable of producing.

The Pink Un: Gibson also struggled against Sunderland.Gibson also struggled against Sunderland. (Image: PA)

The same, as outlined previously, is true of Hanley, who has finished second in consecutive Barry Butler Trophy votes. 

What the pair are showing, just like the rest of their colleagues, however, is that they can't be relied upon to consistently perform, and that's a serious issue.

Even if Norwich do qualify for the play-offs, they'll have to perform well three times in a row against top Championship sides.

Given the unsure nature of a trip to 23rd-placed Huddersfield, that doesn't feel especially reassuring.

Wagner does retain the option to reinstate Omobamidele, and the hunger of a game time-starved young player may provide the hunger this side has been questioned on.

But even the Irishman - who has been linked with a move to Premier League Leicester City - has been inconsistent this term.

So why the unreliability? The answers are likely similar to when asking about any department.

Whether it's confidence, quality, mentality or all of the above, Wagner needs some defenders he can trust, and fast.