Sunderland crashed out of the Carabao Cup on Tuesday evening, as they were beaten on penalties by Oxford United. 

Phil Parkinson's men fell behind in this one with Rob Hall opening the scoring with a well-struck effort midway through the first-half.

But the Black Cats improved in the second-half, and their persistence was rewarded as Marc McNulty fired home from close-range to level the scores with just 12 minutes remaining.

It was Sunderland's strikers that let them down in the penalty shoot-out though, with both McNulty and Will Grigg missing from the spot.

Parkinson will be hoping that his side can now focus purely on winning promotion from League One this season, and will be looking ahead to their next league game against struggling Southend United this weekend.

We look at THREE things we learnt about Phil Parkinson's side from this defeat.

Will Grigg is short on confidence 

It's no secret that Grigg has struggled for confidence in front of goal, which begged the question as to why the Northern Irishman stepped up to take a penalty.

Grigg has only scored two goals in total this season, and blazed his spot-kick over the bar to hand Oxford the advantage in the penalty shoot-out.

Parkinson might feel as though he has to persist with the striker in the starting XI though, as he's already shown he can score goals on a consistent basis in League One, having scored 19 league goals in Wigan's promotion-winning season in 2017/18.

The pressure will already be on Parkinson 

There was some frustration from some sections of the Stadium of Light faithful when Phil Parkinson was appointed, and he hasn't got off to the best of starts in charge of the Black Cats.

This Carabao Cup exit won't have gone down well either, and will only add to the pressure on his shoulders to deliver promotion this season.

That's the minimum expectation from the club's supporters this term, and Parkinson needs to find some consistency in their results as soon as possible, otherwise his days at Sunderland could be numbered.

This could be a blessing in disguise

There's no doubt in saying that Sunderland's main aim this season will be to win promotion back into the Championship, especially after they were defeated in the Play-Off Final at Wembley last term.

Parkinson's side are struggling in their promotion bid though, and currently find themselves () in the league table, which will be a concern for the club's supporters.

But now that they're out of the Carabao Cup, it could be a blessing in disguise, as it could have proved to be a distraction to their league form, which was already suffering due to their cup run.