Curbishley takes West Ham to United tomorrow and Grant said: "Look, I'm not doubting the integrity of West Ham, I don't have a reason to doubt the integrity of Alan Curbishley.
"But I think it's wrong to say things like this because he's involved in the games against United.
"I don't think it's a good idea to say things like this. I cannot be angry. I will not be angry. I do not know what to say about these things, but I think it's wrong. But I do not have any reason to doubt the integrity of him or his club. West Ham are more interested in the success of their club, to win their games. If they have wishes for others, you have to ask them."