"I have been out of the game for sometime and I know I have to perform and prove myself because I was invited due to my ability," Atapattu said in a radio chat show.
The 36-year-old, who was not selected in the original touring squad, was brought in as the 17th member on Thursday following the intervention of the country's sports minister Gamini Lokuge.
The veteran of 88 Tests accused the Sri Lankan selectors of affecting team morale.
"Team spirit decreased because the players became insecure," said Atapattu. "They were performing for themselves to remain in the team.
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Atapattu's return to the national team marks the end of a six-month saga that began at the World Cup, where he was not selected to play in any of Sri Lanka's 11 matches despite being in the squad.
He was also overlooked for the one-day series against Pakistan in Abu Dhabi in May and he pulled out of the three-Test home series against Bangladesh in June saying he was not mentally prepared to play Test cricket.