The team for the Champions Trophy in June will be announced next month and Karthik is hopeful of getting shortlisted from the list of 30 probables.
"My confidence is high at the moment and I am eager to play for India again," said the wicket-keeper batsman ahead of Mumbai Indians' away game against Delhi Daredevils here Sunday.
The 27-year-old last played for India in August 2010 and has been on the sidelines largely because of another wicket-keeper in the team, none other than skipper Mahendra Singh Dhoni.
Karthik could be the second wicket-keeping option in the tournament to be played in England but he also sees himself playing as a specialist batsman.
"If I get picked, it will be as a batsman. You cant't expect me to replace Dhoni behind the stumps.
"I have always been confident in my batting ability. Besides that, I am a decent fielder. My form in the domestic season has also been good. If given the opportunity, I look forward to doing in well in any format," said Karthik, who has played some of his 52 ODIs and 23 Tests as a batsman.
While commenting on his form in IPL, he said he was grateful to the Mumbai Indians for letting him bat at number three.
"I am thankful to Anil (Kumble) bhai, Ricky and John (Wright). I feel I have to deliver for these three top guys.
"At number three, I am expected to score the bulk of the runs. T20 is such a format where the openers and one-down batsman get to play the most of the overs. It is a great responsibility and I hope to carry on playing like this through the tournament."
What makes IPL different from other domestic competitions.
"IPL is a platform where you play the best of the bowlers. Tomorrow I am going to face the likes of Morne Morkel. If you get runs against them, it is a great morale booster. You know you are ready to perform for India. Though the pressure of playing in IPL and for your country is incomparable," signed off Karthik.