Shakhtar showed no mercy at Borisov Arena, embarrassing the Belarusian league champions 7-0 in UEFA Champions League Group H on Tuesday.
The Ukrainian giants blitzed BATE with six first-half goals, while Brazilian forward Luiz Adriano starred with a record-equalling five-goal haul.
Tuesday's forgettable encounter came three weeks after BATE stunned Athletic Bilbao 2-1 for their first Champions League win over Spanish opposition.
Of the 11 players that started against Shakhtar, seven were aged 25 years or under and Yermakovich said the young players struggled to produce another consistent performance.
"It is hard to say when we saw the real BATE – today or against Athletic," Yermakovich said.
"The reason for our defeat is a lack of quality as the young players cannot play at the same level all the time.
"Of course I didn't expect this kind of game. But we can only blame ourselves as we made too many mistakes and this amount of errors is totally unacceptable at this level – you will be punished.
"It is not the right time to draw major conclusions, however."
