The winger is being linked with a return to Everton.
Olic said, “Before I had the opportunity to work with Nikola only in the national team, but now I got to know his qualities even better after I trained him at CSKA. He is a top athlete and a great professional, for several seasons he has been one of the best football players in the Russian championship.
"I believe that Vlasic has already outgrown this championship, it is time for him to take a step forward and develop further. He is different from all the players of the Croatian national team, because he not only knows how to score, but also loves contact wrestling, loves to receive the ball when several opponents are hanging on him.
"In CSKA I always said: 'Give the ball to Nikola', because he copes with it perfectly."