Sehwag, who became the fastest triple century maker in history of Test cricket during the first match against South Africa in Chennai, said too much of "positive attitude" cost him dear in one-dayers.

"I am too positive in one-dayers and I think I have to change that. Sometimes if you are too positive you get out yourself instead of bowlers dismissing you. That is happening to me," Sehwag said.

"So, in the coming one-dayers I will try to play in the Test mode," Sehwag, who scored 319 off 304 balls at the Chepauk last week, said at a press conference to announce IPL team Delhi Daredevils' brand ambassador and team colours.

Sehwag said he had answered his critics, who questioned his Test place, by scoring 300-plus and becoming the highest Indian individual scorer in an innings in the longer version of the game.

"Lots of people had asked why I was in the Test team. I am happy that I have answered them in Chennai."

The hard-hitting opening batsman would not comment whether the Chennai track was flat or not but said he was looking forward to a spinning track in Ahmedabad in the second Test starting on April 3.

"Last time, when we played in Ahmedabad it was a spinning track and we won the game against Sri Lanka within four days.