Pietersen wants England to retain the World Twenty20 title and had indicated it earlier as he wanted to help the team achieve this as well when they defend their title in Sri Lanka in September 2012.
But his retirement has saddened fans and other players as the England and Wales Cricket Board insists on players' availability in both the formats (ODIs and T20) of the game, to ensure that there isn't much difference from the longer format due to their packed schedule.
Pietersen, who announced his retirement from international T20s and ODIs last week, would be missed in all the formats excepts Tests from now on, despite being in top-form having scored back-to-back hundreds against Pakistan as England thrashed them 4-0 to claim the series.
Following Pakistan tour, Pietersen played a vital role in the Sri Lankan tour as well and impressed everyone with his performance in the fifth edition of Indian Premier League as well. This showed the versatility of the batsman.
But team mate Trott has expressed his views on Pietersen's decision, ahead of the third and final Test against West Indies in Edgbaston as they aim for a whitewash having won the first two matches, said he was not totally unaware of the decision, but was disappointed as Pietersen has been one of the most important member of the England cricket team.
"It wasn't a huge surprise," Trott said Tuesday.
"You can understand it in a way, but it's a huge disappointment as well," added Trott
"Kev's his own guy and has to make his own decisions. The team fully support his decision. Whatever he decides to do with his cricketing career is fine."
Talking about the controversial move to rest the players ahead of the third Test, as James Anderson and Stuart Broad have been rested to accomodate Graham Onions and Steven Finn, to ensure the pace-duo are fit for the series against South Africa, Trott said such things continue to happen.
"It's happened in the past, and probably will in the future as well - with the schedule getting busier and busier," said Trott. "It's only right that these things happen.
"Jimmy would have liked to have played, and quite rightly. He's the spearhead of our bowling attack, and you can understand that he will probably be a little bit disappointed.
"But with the bowlers and their heavy workload, it's going to happen from time to time.
"It's not as if you're giving away international caps. We have guys who are vying to play, and whoever takes his place should do a great job."
Asked if the team can seal the third Test and a whitewash Trott said, "We've got the opportunity to win 3-0, so it's really important we drive home that advantage and don't take our foot off the gas."