Saker was also full of praise for Lancashire seamer James Anderson after he became the fourth Englishman to reach 300 Test wickets.
"To me, he is the most skilful bowler in the world," Saker said. "I know Dale Steyn is an outstanding bowler - but when you watch Jimmy and the way he went about things here, he has got more skills than Dale Steyn in his locker.
"Obviously Steyn is a little bit quicker - but when you watch Jimmy deliver those skills, it is just mind-blowing.
"Jimmy, to me, keeps getting better. He is the one player I have coached who is never satisfied with what he has got ... and for him, it would be easy to be satisfied.
"I have never met a guy as good as him who wants to keep getting better. That is one of the reasons why he is as good as he is.
"He has got a body that can play for a lot longer. I hope he can take 400 wickets and be England's greatest wicket-taker. That would be a great feat for him.
"We really hope he can stay on the park for another five or six years."
