Trott flew home from Australia in December, complaining of a "stress-related illness", after only one Test of a series that England would go on to lose 5-0.
Pietersen, who had his England and Wales Cricket Board central contract terminated earlier this year, has challenged his reputation of being a disruptive influence on the team by revealing that he was on hand to counsel Trott as the 32-year-old battled with his demons.
"He has said that I was the first person to notice his problem," Pietersen told reporters. "I told him that he needed to calm down and he was putting too much pressure on himself.
"Contrary to popular belief, I have very good relationship with most of the guys in the English dressing room. I like to look after them. If someone is struggling, I like to go up and put an arm around him."
Trott made only eight runs on his cricketing comeback on Tuesday as Warwickshire faced Oxford MCCU.