Schar missed last weekend’s 1-1 draw against Wolverhampton Wanderers with a “sore knee”.
Head coach Steve Bruce said: “Schar has a sore knee, which he has played with for two or three weeks.”
Bruce had hoped to have the defender back for Saturday’s game against West Ham United, but Sky Sports report that Schar is “unlikely” to be involved.
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Federico Fernandez deputised for Schar against Wolves.