Luiz has not played since last month’s FA Cup semi-final while Cahill has been sidelined since suffering a hamstring injury in the semi-final victory over Barcelona.
With John Terry and Branislav Ivanovic both missing next the May 19 date with Bayern Munich through suspension, Di Matteo’s men will struggle at the back if Luiz and Cahill fail to regain fitness.
“Now we’re trying our hardest working towards next Saturday in the hope they’ll be in the group training next week,” said Di Matteo. Both Luiz and Cahill will miss Chelsea’s final EPL tie against Blackburn on Sunday.
“They’re at similar stages — not available for Sunday, and next week we'll push them to be available,” Di Matteo said.