Phillips pulled out of the England camp due to an injury and was missing from the squad in Leeds’ 1-0 defeat at Southampton last weekend.
Leeds are in a poor run of form with just one in their opening eight league games and the midfielder’s return to the team as soon as possible would be a major boost for the Whites.
However, Bielsa is not ready to rush him back and conceded that while Phillips is fit, he will need more time before he can get back into the team.
The Leeds manager pointed out that the midfielder has been missing for three weeks and playing him on Saturday would be a major risk as Phillips need more training before he can get back into action.
Bielsa said in a press conference: “Kalvin is healthy, but he has not competed for three weeks.
“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.”
It remains to be seen whether Bielsa decides to take the risk of having Phillips in the squad at least on Saturday.