The 20-year-old midfielder has not played for Atletico since a 1-0 defeat at Bayer Leverkusen in the Champions League on February 25.
A blow to the kidney sustained in that game kept Niguez out of action for four weeks but he is close to returning to action after taking part in Monday’s training session.
A statement from Atletico read: “Saul Niguez has been given the all clear after sustaining a trauma in his left kidney.
“The midfielder has been given the green light to return to team training.”
Niguez has scored three goals and provided one assist in 14 La Liga appearances for Atletico.
Atletico return to La Liga action on Saturday at Cordoba before hosting Real Sociedad three days later at the Vicente Calderon stadium.
The Spanish defending champions are fourth in La Liga, nine points adrift of league leaders Barcelona with 10 games remaining.