Spanish site Fichajes claims that Thomas Partey has ‘run out of credit’ at Arsenal after a poor season while AS claim Arsenal will sell him for €30m.

I think it’s fair to say that Thomas Partey endured a slow start to his time at Arsenal.
Hampered by fitness issues, it took him some time to find his feet.
But find them he did.
Until his recent thigh problem, he was, quite simply, majestic in the middle of Arsenal’s team, so much so that his loss for the last part of the season has been a massive blow.
But, if you read Fichajes and don’t watch Arsenal, you’d be forgiven for thinking he was still struggling very badly.

They even go on to speculate that his form has been so poor that Arsenal are considering selling him, only they know they will never be able to recoup the £50m they spent to bring him to London.
Then, there is AS, a much more respectable outfit than FIchajes saying that Mikel Arteta will sell Thomas Partey for €30m in order to buy Arthur from Juventus:

If you were to ask anyone at Arsenal – fans, players or management alike – they would all tell you the same thing – if you offered them £50m for Thomas Partey right now, they’d tell you where to shove it.