Steven Taylor is one of the players whose contract runs out in the summer.
One of those is said to be Steven Taylor, who looks likely to leave in the summer if he is unable to prove his fitness over a run of games between now and the end of the season, with the defender said to want to stay at the club.
Mbabu and Aarons are both 20 and could see their registrations retained by the club beyond the contract as Newcastle would be entitled to seek compensation for their services if they don't end up signing new deals at the club as an alternative to just releasing them.
Other players have either been surplus to requirements for some time, like Marveaux, or have not been in the side for a while as is the case with Obertan.
It seems that with the most recent transfer window, there is a desire to try and spend some money in order to upgrade the squad, and given what happened last season where several players were also allowed to leave at the end of their contract, Newcastle could be quite comfortable to let that happen again.
What is essential, however, is that they retain their Premier League status - something which they made progress on last weekend as a win over West Bromwich Albion took them out of the bottom three if they are looking elsewhere for players to make up their squad.
Either way, between now and the end of the season, all six players are going to have to show a lot of effort and ability in order for the club to put a new deal on the table.