Pietersen's successful reintegration into England's dressing room will be officially acknowledged with the award of his full contract at the end of ongoing tour of India.
Flower confirmed that the extension of Pietersen's four-month contract is all but a formality.
"The contract won't be a problem, Kevin has been excellent in every way," Flower said after England defeated India 2-1 in the just-concluded four-Test away series.
"We don't all always get on with people all of the time, in any walk of life, and everyone has made an effort to make it work. It's been really good fun and he should be very proud of the way he's operated out here both as an individual and as a player," the former Zimbabwe captain added.
Flower knows the value of Pietersen's 186-run knock in the second Test in Mumbai, and said his innings played a big role in England's turnaround in the series after the crushing defeat in the first Test in Ahmedabad.
"In that Test (Mumbai) he showed real skill in Indian conditions on a pitch that turned on the first day," Flower was quoted as saying by The Daily Telegraph. MORE