The Midlands club have not won in the past four matches, losing all of them in all competitions.
They are also out of the Carabao Cup, but are in contention for a Premier League top four finish and are in a good position in the Champions League group stages.
"It’s maybe a mini-crisis (Aston Villa losing the last four games), but it's normal when you play so many games. Unai Emery has done an incredible job. Unai, his staff, the players - they've been amazing,” Petrov told Gambling.com.
"The fans have supported the club perfectly, they've got the right results, they’ve got nine points in the Champions League. You expect teams when they're playing at such a high level to drop in performances at certain times, and I hope that Unai Emery will find the solution and will turn everything around.
“They still have a chance to qualify straight to the knockout stages. They are sitting in a very comfortable position. And if they can manage to do that, then you never know. In the knockout stages anything can happen."
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