The Premier League outfit are understood to have agreed a £25m fee with PSG for the former Manchester United target's signature.
The French club seemed open to letting Moura leave due to his drop in the pecking order at the Parc des Princes following Neymar's arrival from Barcelona last summer.
The Brazilian's teammate has since hit out at PSG's decision to sell.
"I'm sad, because he's a good friend, he's a quality player who was rarely used. I think it's very unfair," The Mirror quotes Neymar as saying.
"He is my brother in football. I wish him the best. Whatever the destination, I hope he will score a lot and he will return to the Brazilian national team.
"He's not just a friend, he's a very good guy. Here he could have been used a lot more but I'm not the owner of the team, not the owner of Paris. For me, he should never be leaving Paris."
Moura joined PSG from Sao Paulo in 2013.