​Newcastle manager Rafael Benitez has reportedly asked for written guarantees regarding transfers if he is to sign a contract extension following the disappointment of previous windows.

The Spaniard looks to have guided the club to ​Premier League safety this term, despite having a squad of '​Championship quality' players, and is due to sit down to talk about extending his current deal at St. James' Park. He supposedly already has one offer on the table from club officials.

Newcastle United v West Bromwich Albion - Premier League

Benitez is happy to do that, but as reported by the ​Mirror, the 58-year-old wants to make sure that he will be given the appropriate resources to compete next season. He is demanding to be promised funds, which he has never really been afforded since taking over in 2016.

Apparently sources have claimed Benitez reached a verbal agreement with the club that he would be able to spend £70m over the course of three transfer windows, but was let down on that.

The former ​Liverpool, ​Real Madrid and ​Chelsea manager was clearly frustrated by that earlier on in the season, shortly after top targets were not landed in the summer.

Newcastle United v West Bromwich Albion - Premier League

Now, Benitez wants to ensure that the ambition and commitment of the club is there before putting pen to paper on the extension every Magpies fan wants him to sign.

He'll be hoping that an injection of cash in the form of a takeover will arrive over the next few months. ​The club is still for sale, with businesswoman Amanda Staveley said to be 'still interested'.​