Interim head coach Gary O’Neil has revealed that Neto will be out for "the long term" ahead of Saturday’s game with Tottenham Hotspur.
The Brazilian stopper was replaced at half time against West Ham United by Mark Travers with a hamstring injury he picked up in the first half.
Elsewhere there was positive news on Dominic Solanke, who was also replaced at London Stadium, with the striker in contention for Saturday’s Premier League clash at Vitality Stadium.
"Unfortunately Neto will be out," O’Neil confirmed.
"It won’t be short term and it’ll be fairly long term, it won’t be a week or two.
"Neto bought a calmness and helped us steady the ship when we had some tough results, but as I said then, I’m delighted to have them both and I have full faith in Mark Travers.
"Dominic Solanke is a lot better than expected, there’s good news and he’s recovered well.
"As a result of that, we’re hopeful of him playing at the weekend but we’ll have to wait and see."
