A day before Halloween, Sunderland endured a nightmare afternoon as they were thrashed by Rotherham United at the New York Stadium in a blow to their promotion hopes on Saturday.

Lee Johnson's side went into the aiming to bounce back from their defeat at home to Charlton Athletic last time out in League One that saw them lose some ground on the teams in and around them in the table.

It was always going to be a real task for Sunderland coming to a Rotherham side that have been on the up of late and are looking likely to be amongst the promotion contenders once again at the end of a season of League One football.

The Black Cats could not contain the Millers' attacking threats at times and they did not look comfortable in the game throughout. This was a performance and result that shows there is a lot for Sunderland to work on even though they have had a good start to the season when you assess their overall form this term.

With all that in mind, we take a look at THREE things we clearly learnt about Sunderland following their defeat at Rotherham.

Sunderland's vulnerabilities on show again in another heavy defeat

The Black Cats had already endured one miserable away day this season so far in League One with them suffering a four-goal loss away at Portsmouth where their defence was exposed and there were not enough players for Sunderland who reached their usual standards of performance.

This trip to Rotherham exposed those same issues within Sunderland's squad once again on Saturday. Johnson's side were totally out fought by the Millers and they went under at times when they were being put under real pressure by Paul Warne's side. That is something that you can not do if you are wanting to secure automatic promotion.

There is of course the factor that Sunderland went down to ten men once Aiden McGeady had been sent off. However, a lot of the damage had already been done before that point and the Black Cats were trailing by two-goals at that stage in the game anyway.

Johnson had to apologies to Sunderland's away support after the game and labelled the performance as 'men against boys.' It is a major concern that Sunderland have now shown these kinds of frailties away from home twice already this term and it is something that they have to address quickly.

Aiden McGeady continues to struggle

Last time out against Charlton, Aiden McGeady was far off his best form with him not doing enough to impact the game with the quality that he has. That played a key role in the Black Cats being unable to create enough in the final third to get anything out of the game at the Stadium of Light.

Johnson showed faith in McGeady by keeping him in the starting line-up for the trip to Rotherham, but the playmaker once again endured a very difficult afternoon for the Black Cats. He was ineffective going forwards and did not really offer enough when he had the ball at his feet throughout the 56 minutes that he was on the field for.

In total, McGeady failed to deliver a single accurate cross, failed to complete a single a dribble and also did not record a single key pass. There were also times where he did not track back strongly enough to help out the Black Cats' defence.

McGeady's afternoon was then compounded by him picking up a red card for a second bookable offence just ten minutes into the second period. That pretty much put the game beyond the Black Cats' reach.

The playmaker's quality is not up for doubt, but at the moment he is not performing and a suspension could be a good thing in the end because it will give him the chance to sit one out and try and regain his form.

Ross Stewart the one bright spark as he continues to be Sunderland's talisman

In a game that saw pretty much all of Sunderland's starting players deliver a performance that was nowhere near good enough at Rotherham, Ross Stewart was at least once again one real bright spark for the Black Cats to give them hope that they can achieve better results in the coming matches.

Stewart was able to reach the ten-goal mark for the season in League One against the Millers with him firing home an equaliser after Michael Smith gave Rotherham an early lead. The goal was typical of the forward's quality so far this term and he made the finish look a lot easier than it should have been.

The forward also struck the woodwork with a great strike from distance as well as he carried Sunderland's only major threat to Rotherham's defence.

Therefore, despite being left isolated for most of the contest, Stewart was still able to impose himself on the game in spells and show what he can do for Johnson's side.