The Australian star missed two headed chances during the match – chances he would usually bury – whilst teammate Leighton Baines hit the crossbar from a free-kick on a trying afternoon for the Merseyside club.
On his Twitter page, Cahill said he understands the frustration of the Toffees fans who have endured a tough week in relation to the clubs off-field difficulties.
"EFC fans can understand our frustration, I'm gutted and not much to say," he wrote.
"It's even harder to take after me missing those chances."
Everton conceded in the 31st minute when Tommy Smith scored for the R’s and were unable to hit the back of the net in what was a disappointing start to the 2011/12 Premier League season for the men from Goodison Park.