The interim boss made the trophy a target when he replaced Roberto Di Matteo in November, but the midweek draw with Southampton left his side 13 points behind leaders Manchester United.
"In terms of the league, I don't think we can do it," Benitez said ahead of the first of Sunday's two Sky Live games with kick-off at 1:30pm.
"But the Capital One Cup is there, the FA Cup is still open and the Europa League is still open.
"I just have to give the team the confidence that we can win against anyone. If you have that belief it becomes easier.
"The team is very close. We have John Terry and Frank Lampard back from injury. Now we have to be more consistent."
Arsenal travel to Stamford Bridge and Benitez's men will be looking to end their poor home form - having won only one of their seven previous Premier League games at the Bridge.
Arsene Wenger's side have won away at Chelsea more often than any other league club, and Wenger stated earlier this week he was expecting a thrilling showdown.
Not immune to criticism himself, Wenger also commented on Benitez's reproach from Blues fans. He said: "I feel sympathy for every manager until the day I play against him.
"Then the sympathy goes and comes back after the game - not always straight after the game, sometimes it is some time later. We are all in the same position.
"We know we are in a fragile job and that the confidence is very important but it is a job where you have to take care of your own team."