Koeman won't consider the Frenchman for selection against Bayer Leverkusen today as he remains upset over being denied a move to Tottenham.
"The situation is difficult, the player makes it difficult," Koeman said.
"I spoke to him with our chairman and the situation has not changed - we don't sell Schneiderlin and he has to accept that.
"Tomorrow he is not in the squad. He said he is not physically and, even more, mentally prepared for tomorrow.
"On one side I can understand that. We told him to take the weekend off and think about the situation.
Koeman added: "He will continue as a football player of Southampton. Now it is up to him."
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