Speaking in the post-match press conference, Fleming said Stokes was "progressing well" and added that he had taken steps towards full fitness in the month since England's second Test in New Zealand.
"He had a fair amount of time off between the last Test match and getting here, and he had some medical work done on the knee," Fleming said. "We want to do the right thing by Ben and make sure that he's 100% ready to go.
"He's not there yet and that includes bowling form. We are working closely with him, but he's making really good progress. We're really happy with what he's done so far and I think he feels pretty positive about the progress he's made."
Super Kings only used five bowlers in their defeat on Friday night, with Moeen Ali and Shivam Dube both unused. They will soon have Sri Lanka's Maheesh Theekshana and Matheesha Pathirana available after international duty, and Fleming said that Stokes' return to fitness would provide a boost later in the season.
"That's another addition to the side, when he starts bowling," Fleming said. "We've got some good players to come in, and we've introduced some players today, so it's not all bad."