The 32-year-old midfielder, who has been capped 34 times by France, joined PSG last week on a deal until June 2019. He was a free agent after leaving Al Jazira in the United Arab Emirates at the end of December.
However, there are doubts about the current state of fitness of the former Chelsea, Arsenal and Real Madrid player, and he is unlikely to start the match in Brittany.
Diarra was signed to provide cover for the ageing Thiago Motta, who is still struggling with a calf problem and will not feature.
Kylian Mbappe also returns for PSG having missed his team’s last two matches with an injury suffered in the 2-1 defeat at Lyon on January 21.
PSG are looking to win the League Cup for the fifth year running. The other semi-final will see Monaco play Montpellier on Wednesday.
French League Cup semi-final fixtures
Tuesday (2005 GMT)
Rennes v Paris Saint-Germain
Wednesday (2005 GMT)
Monaco v Montpellier
