Yorkshire coach Jason Gillespie has hailed Australia fast bowler Mitchell Johnson, who is on the verge of his 300th Test match wicket.
The left-armer has eight wickets in The Ashes so far and has caused England plenty of problems with his aggressive, short-pitched bowling, and Gillespie has labelled him the tourists' key man.
He wrote in The Guardian: "Johnson, in particular, is at the peak of his powers and his low-slung action, sending the ball down at high velocity from that awkward angle, is causing them problems. For me he is Australia's creator of havoc and his captain, Michael Clarke, is using him beautifully.
"The unpredictability of his deliveries is making him very tough to face. Some swing in, some don't, and that bouncer is world class. Johnson sits one wicket short of 300 in Test cricket, and one run short of 2,000 with the bat, and these two milestones will represent deserved achievements for a player who has blossomed as his career has progressed."
Johnson made his Test debut in 2007.
