Jimmie Johnson remains optimistic about title defence despite his tough start to the Chase

The reigning champion finished 18th on Sunday in the second round of the Chase at Loudon after being unable to make much progress in the second half of the race, following a four-tyre pitstop that made him lose track position.

In the closing stages of the race he clashed with fellow title contender Kyle Busch while battling for position and contact at Turn 1 left Johnson with suspected damage to his car's steering.

"It was just the end of a bad day," said Johnson. "We didn't have a car like we thought we would... After practice, the car was just great. [In the race], it just didn't have the speed and then track position was so important and some pit calls didn't work out our way. But we'll take this one on the chin and go on to the next one."

Johnson seemed frustrated on the radio at one point, telling his crew chief Chad Knaus that his "cheerleading" was "annoying", as he struggled to charge through the field.

"I think he was just being optimistic there about what was left in my back pocket; but my suit doesn't have any back pockets," Johnson explained.

Despite never being ranked as low in the Chase as he is at present, Johnson was able to rebound last year despite not getting his title campaign off to good start in the Chase. Although he is 10th in the standing now, he is only six points behind Hendrick Motorsports team-mate Jeff Gordon, who ranks fifth. The gap to points leader Tony Stewart is up to 29 out of a maximum 48 possible per race.

Up ahead in the Chase schedule is Dover, where Johnson won a year ago and where he has won three of his past five races, including two play-off events.

"My optimism is still high," says Johnson. "We didn't get the result [at Loudon], but if you look at Chicago where we were last week, we didn't get the finish that we should have had, but we had a tonne of speed and there are a lot of 1.5-mile tracks on the circuit.

"These first two races did not start as we had hoped that they would, but eight to go, there's still a lot that can happen."

Johnson has been unable to avoid trouble for the past three weeks, clashing with Kurt Busch at Richmond right before the Chase started and then running out of fuel last week at Chicagoland Speedway, though he took a 10th place finish despite that.