Ahead of their clash with Wolves, Bielsa confirmed that England midfielder Phillips is not quite ready for a return to his squad.
"Kalvin is healthy, but he has not competed for three weeks," he said. "If he played on Saturday it would be far too quick. After three weeks out it's necessary for more training.
"At this stage he has done sessions for recovery and physical prep and progressive work with the ball.
"To think of him for Saturday would be too soon before his best."
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