Speaking on Thursday from Bayern's winter training camp in Qatar, Nagelsmann told reporters Mane was making better than expected progress in his return from the right fibula injury which ruled him out of the World Cup.
"He (Mane) is an important player. When everything goes well, it could be that he's there against Paris," Nagelsmann said.
"But we will see.
"In my mind, I'm not counting on him for the first game against Paris."
Mane has scored six goals and made three assists in the league since making the move from Liverpool to Bayern in the summer.
Six-time Champions League winners Bayern travel to Paris for the first leg clash on February 14, with the return fixture in Munich taking place on March 8.
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