Diawara is the salubrious linchpin of Sarri's midfield by functioning as the conduit between Napoli's defence and attack, offering locomotion in tight spaces, which bodes well for potentially playing with Pogba who is also press-resistant, physical attributes to dispossess players with consummate ease, and the speed to press aggressively and track back, he brings a much needed semblance and serenity to Napoli by having the confidence to not go for transparent passes, and this is exemplified by his propensity to make vertical passes which breaks the press. He's one that predominantly favours screening the defence instead of diving into challenges and leaving cavernous gaps behind.
Another option is Lorenzo Callegari. From the little I've seen of him, I think he could be worth a punt. His contract runs out in 2018, and as far as I know, he's yet to receive a contract extension. I think he'd be receptive to the idea of leaving PSG, as according to reports, he wasn't disconcerted with the possibility of going to Zenit