Marcelo was a doubt for the game after suffering a hamstring injury during a LaLiga match against Real Betis last month.
But the Brazilian was back in training for Madrid on Thursday, giving the 29-year-old a chance of facing PSG at the Parc des Princes on March 6.
Marcelo scored Madrid’s last goal in a 3-1 defeat of Paris Saint-Germain in the opening leg.
PSG coach Unai Emery is set to be without star man Neymar due to a foot injury.
Luka Modric and Toni Kroos are on the sidelines for Madrid, the midfielders out of action with hamstring and knee injuries respectively.