What's more, the Blues have also kept clean sheets in nine of their last 11 matches against Boro in all competitions.
Boro last beat Chelsea back in August 2006 when Mark Viduka scored a winner in stoppage time.
If the hosts are to reverse those fortunes at the Riverside Stadium on Wednesday night, they will have to do so without England youth international Josh McEachran. The midfielder is ineligible to play because he is on loan from Chelsea.
However, having come on at the weekend as a substitute following a spell on the sidelines, striker Scott McDonald should be included in the starting lineup.
Cahill's absence is likely to hand a starting opportunity to captain John Terry, who has found opportunities hard to come by ever since his recovery from a knee complaint.
The winners of this tie will take on Manchester United at Old Trafford in the quarter-finals.
Possible starting lineups
Middlesbrough: Steele; Bikey, Williams, McManus, Friend; Carayol, Leadbitter, Dyer, Hailliday; McDonald, Main
Chelsea: Cech; Ivanovic, Luiz, Terry, Bertrand; Mikel, Ramires, Marin; Hazard, Torres, Mata
Sports Mole says: 1-2