"Just in terms of his desire, and if he has got any ambitions of playing for India for a long, long time, he should change his habits," Donald, who is here to do commentary in the ongoing Champions League Twenty20, told Cricinfo.
The 42-year-old former coach of English county Warwickshire, where Sreesanth played earlier this year, said though a good bowler, the Keralite has allowed emotions to get the better of him way too often.
"We wanted someone who could overstep the line a little bit and we know how Sreesanth can do that. But I knew I could control him, and we chatted about it quite a lot."
Asked specifically where Sreesanth, who hasn't played for India for close to two years and has a history of on-field showdowns with opposition players, has been going wrong, Donald said he has been lacking in focus.
"First of all, his training habits are not good and the way he goes on to the field need to change. Then, he doesn't put enough time on specifics," he said.
"I know he is aggressive, he is passionate and I know he just boils over with emotions in the heat of the battle. There is nothing wrong with that but I just think sometimes he lets himself down," he pointed out.
Donald said the pacer's temperament would be quite frustrating to manage for any coach or teammate.
"It is frustrating in a way. I do have a problem with that because it is not the real him. It is false in the way he conducts himself. You need to be in serious form to back your body language.
"Off the field he is a little kitten - he speaks the right thing, comes and says 'sorry for this and that'. But my message to him is he cannot come off the field and apologise. It is too late," he said.
Donald also pointed out a technical flaw in Sreesanth's bowling action.
"He has got a slight technical glitch where he sits back and doesn't really use his front arm well, which makes him swing the ball a bit early," he said.