Swansea boss Alan Curtis insisted referee Graham Scott was “out of his depth” after Sunderland’s win at the Liberty Stadium on Wednesday night.

“I think he got all the major decisions completely wrong," said Curtis.

“I won't say it has cost us the game as you don't know how it will play out but it has had a major bearing on the game. Unfortunately he did look out of his depth.”

It must be unbelievably frustrating as a manager when referees' calls go against your team – especially when you are fighting for every point, but there really is no use in complaining about it.

It has happened since the dawn of football.

The bigger worry for Swansea chairman Huw Jenkins is whether it is actually Curtis himself who is out of his depth - having now appointed former Udinese manager Francesco Guidolin as head coach until the end of the season.

Even so, Curtis will remain working alongside the Italian and will presumably continue to have the same influence for which Jenkins initially entrusted him with the role, but has so far brought little reward on the pitch.

The defeat to Sunderland means the interim manager has managed just one win in the seven matches since he took over from Garry Monk. Four of them have been losses.

In their last two games, they have been beaten – at home – by a team that were thought to be relegation certainties, and lost away to a side three divisions below them.

And they have shipped seven goals in the process.

Until the weekend, you could make a good case that Curtis wasn’t doing too badly. There is no shame in narrow 2-1 defeats to both Manchester City and Manchester United, or draws with West Ham and Palace.

And West Brom were beaten at the Liberty in his only win so far.

We’ll even leave the defeat to Oxford one side. Strange things can happen in the FA Cup – especially when that competition is a distant second to Premier League survival in your priority list.

But Sunderland should have been there for the taking. Ripe for the picking.

This is a side mired in the bottom three, who at the time had just one win in their last eight games – and that was against an absolutely woeful Aston Villa side.

Plus they were playing under the lights and in front of a full house at the Liberty - the sort of game Curtis and Swansea simply must be getting maximum points from if they are to pull away from the bottom three.

They have five points from six games since Curtis took charge. If they continue at that rate for the rest of the season, they won’t even reach 35 points. The last time that would have been good enough to keep them up was 2010.

And next up is Watford. Again, at home. Again, a night match, and again, no doubt, the Swansea fans will pack into the Liberty to roar on their side.

Yes, Watford are having a tremendous season for a promoted club, and currently sit proudly in the top half.

But this is still a team fresh from the Championship playing away from home at an established Premier League side.

Just like the Sunderland tie, it is another eminently winnable match, on paper.

But if Curtis - in whatever his recently-adjusted role entails - is to help keep the Swans afloat this season, then he must do more to make sure that they deliver on the pitch.

Swansea v Watford betting

Match special: 9/1 - Odion Ighalo to score first and Watford to win

Premier League betting