Cellino sacked Rosler yesterday and has appointed Evans on a 12-month rolling deal to become his 6th head coach at Elland Road since he took over in April 2014.
Evans took charge of training today at Thorp Arch and Cellino claims he likes the former Rotherham boss' fiery personality.
"I used to hate him because he is a fighter," said the Leeds owner and chairman in the Mirror. "I didn't like playing against him because he gives his teams his personality.
"He's a tough coach and I want that character in our team. He manages with passion and our team has not been playing with passion.
"I wanted them to play heavy rock-football, but instead it was like Country music."
Rosler lasted just 12 games and the final straw was Saturday's defeat at home to Brighton, which meant the German never won a match at Elland Road.
Cellino was also annoyed by Rosler's pre-match claims that Leeds could not win promotion this season.
"Why did he say that?" said Cellino. "The fans want to dream, so why did he say that?
"To say that after 11 or 12 games is wrong. That is not right for the fans.
"I watched the game on Saturday and in the second half, we were just trying not to lose. We were not trying to win. That is not good enough.
"I did my best to help Uwe, but in the end, I could not see even a patch of blue in the sky, just cloud, cloud and cloud."
Cellino also appealed to the unhappy Leeds fans to understand why he had sacked his fifth coach in just 18 months.
"Everything I do is to try and make Leeds better," he said. "It hurts me deeply to fire a coach and I didn't sleep last night after speaking to Uwe yesterday.
"But else should I do if I cannot see things getting better?
"It's easy to blame the coach and it is not just his fault. I was the one who brought him here, so I have to take responsibility also.
"It was my decision to bring him and so I have to take responsibility if things are not working."