Last season's Czech Republic champions have been on the slide since Priske left for Feyenoord.
Berger, who played for Sparta later in his career, told Tribalfootball.com: "Yeah, I mean, Sparta Prague, obviously, the manager left. He's been at Sparta Prague for two years, won the league twice, won the double the year before. So, obviously, you know, he had an offer from Feyenoord, I think.
"So, the assistant coach stepped in and they had a decent beginning of the season, but then everything started to go wrong. I mean, I just don't know why. But obviously, you know, I think they had been waiting for a win for 45 days until last week.
"I saw the game (against Bohemians). But they're not really playing well and they're not even close to what they have been last season."
Berger also had a word for Sparta's home collapse in the Champions League against Atletico Madrid.
"No, listen, you can (lose)... Obviously, Atletico Madrid is one of the top teams in Europe, but 6-0? I was watching the game and it was embarrassing."
Asked about Lars Friis, who stepped up to take charge after Priske's exit, Berger admits a decision may need to be made.
"Well, with the season breaking in a couple of weeks, it is going to help. They've also missed their two key players, Lukáš Haraslín and Veljko Birmančević, who is now back.
"They're gamechangers for them, so it's been difficult to win games without them.
"I don't think it makes sense to change the manager, but because we have a break in the winter in the Czech Republic maybe that would be the right time, but I don't know."
Asked about youth development in the country, Berger says rather than the U21s, fans should look further back for talent with the potential of making it big in the game.
He said, "I need to be following the Czech U21s, they qualified for the finals in Europe in Slovakia, they went through Belgium in two games but I was watching both games and if I had to choose a player... I mean it would be probably player from the other side but not from the Czech team.
"But there are a lot of good players under 16, 17, under 15, but it will take time before they will get through to the top of football. But if I'm looking at the U21s, I don't really see anybody who can be the rising star in Czech football."
However, Berger also said: "Don't get me wrong.
"It's great they qualified. But from the football point of view, when you're looking for players, I think Belgium was a much better side. And they have a different philosophy.
"As soon as they see good youngsters, they try to put them to the first team quickly. So their U21 team, they were missing four players that were already in the senior team."
- Patrik Berger was speaking to Tribalfootball on behalf of spelbolagutansvensklicens.co