Davy, Sandro, Vlasic are all worthy of another chance.
I think it's massively harsh on Vlasic to count him as a disappointment as well.
Also, two of those players are 23 and 20 respectively.
Personally I'd keep hold of all three of them for pre-season. If they don't cut it under Silva, then fine. But we need to know.
The likes of Mori, Martina, Williams, Mirallas - we know they aren't good enough. Mori proved easy enough to shift because he's a good age and wages wise wasn't on loads. Martina is tosh so will be more difficult. Mirallas and Williams are the issue.
Silva has already said Schneiderlin will be given a chance. If he thinks he can get the player out of him that was here in early 2017, then it's a good move. It is a risk though so the decision will have to be made quickly.