Petrov, who retired from playing in May following a battle with acute leukaemia, was appointed as assistant to Villa Under-21s boss Gordon Cowans in the same month.
And the 34-year-old former Bulgaria and Villa midfielder and captain - now in remission for 12 months - has admitted he has found the job to be "a little too much too soon".
He said on www.avfc.co.uk: "The entire Villa family has been incredibly supportive and I am so grateful for this, as is (Petrov's wife) Paulina and my close family circle.
"I love my new role with the club, I love the involvement and I want to continue to make a valid contribution.
"In order to do this to the best of my ability, however, I need to take some time away as I have found the day-to-day demands of the job to be just a little too much too soon.
"I intend to spend some time with my family and in six months or so we'll assess how everything is then.
"Physically, I just need to build myself up some more before I can throw myself into things in the only way I know how which is full-on commitment.
"I appreciate very much the understanding shown by the club.
"I have spoken to the manager (Paul Lambert) and to the chief executive (Paul Faulkner) and they, in particular, have been great in helping me to reach a decision which I feel is the right one while also reassuring me that the club will always be here for me, which I know in my heart.
"Thank you again to all of the fans and I will very much remain a part of the Villa family throughout the coming six months or so while I concentrate on getting stronger and, physically, being back to myself."
Lambert said: "We are extremely grateful at the club for the commitment, effort and dedication which Stiliyan has brought to his role.
"I fully understated his position and the club is entirely supportive of his decision.
"It's a case just now of it having been a bit too much too soon at this moment in time but there will always be something here for Stan.
"He's totally aware of this and we'll revisit things when he feels he is fully ready for that day-to-day involvement again.
"One thing is certain, he will always have a part to play at this football club and everyone at Aston Villa will echo that sentiment."