When Jesus was before the high priest, he never made any direct claims about himself. This exchange is what led the high priest to call Jesus a blasphemer: The high priest said to him, “I charge you under oath by the living God: Tell us if you are the Messiah, the Son of God.”
“You have said so,” Jesus replied. “But I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven.”
In his statement Jesus did not indicate he was talking about himself, even though we now know he was.