Talking with reporters after practice Tuesday, Kiffin was unabashed in his praise for Johnson.
"I will be shocked if he's not a great player in this league," Kiffin said. "I (have) nothing but the highest respect for the individual and the player. I thought he was phenomenal, I had never seen a guy like him."
During his pre-draft evaluations, Kiffin flew to Georgia Tech to see Johnson's private workout. Impressed might be an understatement for how Kiffin felt afterward.
"He doesn't even stretch, he just goes out and jumps 44 inches and didn't even come close to dropping a ball at all. I'm sure they're really excited about him and I'm sure he'll be a great player in this league."
Stopping Johnson and the rest of the Lions receivers will be left up to Raiders cornerbacks Nnamdi Asomugha and Fabian Washington. Asomugha offers a better physical matchup and is coming off his breakout 2006 season when he led Oakland with eight interceptions, but defensive coordinator Rob Ryan has been reluctant to move his cornerbacks around.
That means more pressure on Washington, who played well as a rookie and at the start of last season before tailing off.
Meanwhile, Kiffin said there was no news to report on Russell's continued holdout. The No. 1 pick in the draft has yet to sign his first NFL contract and will have to watch his team's first game on television rather than from the sidelines.
Kiffin maintained his stance that he cannot focus on Russell's absence and instead will concentrate on the players Oakland does have.
"It's nothing against JaMarcus," Kiffin said. "That's just where your energy needs to be."