Cook, 27, will captain the Test team for the first time as England look to end their 28-year wait to beat India in their own backyard.
And the Essex batsman was happy to admit how important it was having the South African back in the team for their sub-continental challenge.
“I am just delighted to have a world class player back because I know that is how we get our best results,” said Cook.
“I am really pleased with the result that we have got.
“Clearly it has been a difficult two months for me as a captain but the best possible outcome has happened.”
Pietersen will fly to India from South Africa where he is currently playing in the Champions League T20 with Delhi Daredevils.
Cook says everyone within the squad must take responsibility to help foster the best team spirit possible to ensure there is no repeat of the soap opera which has raged between the ECB and Pietersen since August.
The positive harmony of the team has often been identified as the key behind England’s rise to the top of the world rankings in 2011, and Cook is keen to restore that unity.
“Clearly we are always going have to work with every member of the side,” he added.
“There will be different issues cropping over the next couple of years, I am sure, but we know how important team spirit is and we know that we are going to work hard to protect that.
“That is every member of that 17-man squad for this series and the management as well.”
MORE: The latest football news
MORE: The latest tennis news
BIOGRAPHY: Marcus Rashford