The Frenchman has been sidelined since picking up a knock in Los Blancos' 3-0 win over Celtic in the Champions League on September 6.
The report claims that Benzema has been fighting to try and regain his fitness and has been training in two blocks.
He has done 45 minutes of gym work and worked with the entire squad to work on tactical work.
Benzema is set to be a doubt until the very last minute leading up to the clash with Atleti at the Wanda Metropolitano Stadium.
The French forward is eager to be part of the Madrid derby.
He has made a brilliant start to the new season before his injury, boasting four goals and an assist in six appearances.
The remarkable proflifc form he showed last campaign in which he finished top scorer in both La Liga (27) and the Champions League (15).
Real Madrid head into their encounter with Diego Simeone's side in fine form. They lead the La Liga table, winning all five of their opening fixtures.
Carlo Ancelotti's men also won 2-0 midweek against RB Leipzig in the Champions League.
Meanwhile, Lucas Vasquez is the other likely absentee.
The Spaniard is out with a right thigh injury that he incurred during the side's 4-1 win over Mallorca on September 11.
Real Madrid striker Benzema loves the Madrid Derby
Benzema has had huge success against Atleti in the past which may be another reason he is so eager to return to match fitness for the clash.
The Frenchman has faced Los Rojiblancos on 37 occasions. He has been on the winning side on 17 occasions, drawing 11 and losing nine times.
He has scored seven goals against Atleti whilst providing four assists.
Benzema scored the opener in last season's meeting between the two sides at the Bernabeu, with Real Madrid going on to win 2-0.
Atletico have made a topsy-turvy start to the new season. They have won three of their five opening league fixtures.
They were beaten 2-0 by Bayer Leverkusen midweek in the Champions League. Simeone's side were unfortunate not to have been handed a penalty in that game.
Atleti did beat their Madrid opposition 1-0 at the Wanda Metropolitano Stadium last season.