"It's hard to play red-ball cricket when you aren't consistently playing that format," Kuldeep told reporters here after turning up for India 'A' in the second unofficial Test against South Africa 'A'.
"If you aren't a regular in this format, it takes time to get into your rhythm. When you are consistently playing limited overs and suddenly switch to Tests without much preparation, it will be tough to excel.
"You need to bowl long spells, play practice games, to understand field placements and to know how to pick wickets. It was important for me to come here (in the India 'A' game) and bowl as many overs as possible. There is still plenty of work to do," he said.
Kuldeep is part of India's test set-up although he was not played in the West Indies with all-rounder Ravindra Jadeja preferred over him and Ravichandran Ashwin.
In home conditions with the three Tests against South Africa coming up, India can play two spinners and Kuldeep will want to get a look in.
"When three spinners like Ashwin, Jaddu and I are in the squad, it's challenging to pick the right combination. You need to be ready to grab your chance. Of course, there is pressure because you only get a few chances, and you have to make full use of them," Kuldeep said.
Kuldeep was not picked for India's T20I squads for the West Indies tour and the ongoing home series against South Africa.
"So far, I have done a good job in limited-overs format. I feel very comfortable with the white ball," Kuldeep said.
"I am not worried about not being picked for the last two T20I series. Maybe the selectors felt I needed a break. Maybe the team thinks some changes are required. I respect that, and I have no complaints. I see this as an opportunity to do well in Tests."
Asked about wrist spinners, Kuldeep said they are very much in demand. "There is no doubt that wrist spinners are dominating the world. But sometimes, when you try to stop runs, you actually turn out to be expensive. We need to work on our accuracy. You need to accept that you do get hit for runs and work on being economical."