The Arsenal centre-forward scored all three goals in Sweden's 3-1 World Cup win against Ukraine.
Rebrov said afterwards: "Gyökeres played fantastically and made the difference tonight.
"He showed his quality, why he plays for Arsenal and why he is one of the best strikers in Europe."
Sweden' coach Graham Potter was, of course, also pleased with Gyökere's performance.
"Viktor's performance was obviously incredible. Besides the goals, because scoring a hat-trick is one thing, I thought overall his target play and his defensive responsibility for the team were part of an incredible performance," he said.
When asked what he said to Gyökeres before the match, Potter jokingly replied: "I said just go and score a hat-trick. No, the great thing about the victory is that everyone was on board. The team mentality was brilliant.
"Viktor's performance is the highlight and rightly gets the headlines. He was incredible. But he will say that the team behind him is also great. We can still improve. This is the beginning of our journey together."