The 2015/16 season was a desperately disappointing campaign for Newcastle United as it ended with a second relegation in the last decade.

While the season ended on a high with Rafa Benitez taking charge and then hammering high-flying Tottenham 5-1 on the final day, some players simply underperformed.

On paper, the Toon Army have one of the strongest squads in the division - if not the best - but Benitez is going to need to get some of his underperforming stars back in form if the club are going to bounce back at the first attempt.

At this stage, it looks unlikely that some of the clubs bigger stars will be playing in the second tier next season, with the likes of Georginio Wijnaldum and Daryl Janmaat being strongly linked with moves away from St James' Park.

But the bigger names that have disappointed recently, and there are a few, will likely stay with the club and will be tasked with helping them get out of the Championship at the first time of asking.

Here are THREE Newcastle United players that simply must improve next season!

Jonjo Shelvey

Back in January, then Newcastle manager Steve McClaren decided that the best way to get his side out of relegation trouble was through spending big on new signings, Jonjo Shelvey was one of these players.

He joined for a fee reported to be £12m and not only did he fail to keep his side in the Premier League, but his performances also failed to live up to his eight figure price tag.

The 24-year-old ended the season dropped by Rafa Benitez and if he is one player who simply must improve if the Toon Army are to be successful this season.

Aleksandar Mitrovic

Another big money buy from the previous manager, Mitrovic actually didn't have a bad goalscoring record last season - 9 in 34 games - but his performances were still sub-par.

One of the 21-year-old's biggest problems was his discipline. The Serbian international has been sent off seven times already in his short career and that number will only rise in the Championship if he continues with his ill-mannered challenges.

A season in the second tier could be very beneficial for the Serbian but given his side's lack of striking options at the moment - Dwight Gayle and out-of-sorts Papiss Cisse being the only senior option - Rafa Benitez is going to need him to play as many of the 46 league games as possible.

Ayoze Perez

The 22-year-old forward, a €2m signing in the summer of 2014, certainly has the potential to be a top player, links with Barcelona and Real Madrid prove that, but the application is lacking.

He has the quality to change in the game in a second but he needs to start producing that sort of display on a more regular basis if he is going to realise his potential.

Working with Rafa Benitez will help him towards that, but the former Spain under-21 international is going to have to apply himself as well.

Newcastle fans...Do you agree? Which players do you think must improve next season? Will you bounce straight back to the Premier League? Let us know what you think in the comments below!