Cahill (knee) and Cole (hamstring) are stepping up their recoveries, but both are still likely to miss crucial matches before the end of the season, including Thursday's Europa League quarter-final second leg at Rubin Kazan.
"The feeling from both is really good," Benitez said.
Centre-back Cahill has had a knee operation after being ruled out of England's World Cup qualifiers with San Marino and Montenegro last month.
The 27-year-old has not played since suffering the injury in the Premier League defeat of West Ham on March 17 and is set to miss a further two weeks or more after the minor meniscus operation, but Benitez is optimistic a return is near.
"He had an operation," Benitez said. "We did it very quickly on the Saturday of the Southampton game (March 30)."
Cole suffered a hamstring injury in the Easter Monday win over Manchester United, two days after the Southampton defeat in the Premier League.
Cole's understudy Ryan Bertrand (illness) is doubtful for the trip to Moscow, when Chelsea will bid to confirm their progress to the semi-finals following last week's 3-1 first-leg win.
If Bertrand joins Cole in missing out, Benitez could field Paulo Ferreira or young midfielder Nathan Ake at left-back at the Luzhniki Stadium.