Miller, the Cumbrians' leading scorer this season with 15 goals, missed the last month of Carlisle's run-in when they narrowly missed out on a play-off place due to a groin injury that required surgery.
"I have plenty of work to do to get myself fit but I just want to be back at it now," Miller told the club's official website.
"At the moment I'm even struggling to get out of the car and do simple things like that because of the operation I had, but that can only improve.
"My focus is on being ready as quickly as possible so that I can get back to playing well and hopefully scoring more goals next season."
The 28-year-old Scot, a free signing from Middlesbrough last summer, was voted player of the year by both the club's fans and fellow players at the end-of-season awards.