Cillessen and Areola are good keepers and if Real are considering giving Kovacic, why not Navas?
You are missing the point however. A decent goalkeeper instead of a (potential) great one will not make a big difference to this team. After Neymar moved, goalkeepers like Leno, Perin (Juve) have moved. The Chelsea board has grossly misjudged the goalkeeper market this summer and are now paying the price with a panic buy. Questions need to be asked about it.