Simpson said on Thursday that the team had been in reasonable form but had not reaped reward for effort.
"We feel like we have been improving from round one to round 12 and playing good footy of late, but not getting results we are after," Simpson told Melbourne radio station SEN.
"It's disappointing to be 6-6 and being in most games but not getting the results."
Simpson has spent much of the season playing across half-back, adding run and skill to Carlton's back half. He said the trust among the defenders was growing each week.
"I am enjoying going back there. It's a good group that's growing confidence in each other during games.
He said the move to the backline was dictated by coach Mick Malthouse's wish to get better ball users in the defensive part of the ground and to provide some support for the in-form Andrew Walker.
"He wanted to get someone down there who wants the ball and can kick the ball like Andrew and I was happy to have a go at it."
Simpson said the Blues know what to expect from the Sydney Swans when they clash at the SCG on Friday night.
"They're probably the best at sticking to structures. [They do] it their way for longer than the opposition can stand up for," he said. "We just have to match them."
