Stephen Harmison is again performing as a world-class fast bowler and would be ready to carry his prolific form on to the international stage, according to the coach who knows his game as well as anyone.

Geoff Cook, the Durham head coach, watched Harmison take five wickets against Yorkshire on Saturday, an impressive performance that was also witnessed by James Whitaker, the England selector.

The pace bowler will learn today whether he has done enough to earn a recall for the second npower Test against Australia, which begins at Lord's on Thursday.

Harmison took his wickets on an easy-paced pitch at Headingley Carnegie that has frustrated other bowlers, his combination of pace and bounce enabling him to tear a hole in Yorkshire's top order.

“He had to thrash himself to get anything out of the wicket, but he always puts the effort in for Durham,” Cook said last night. “He's a tall lad and a world-class bowler, he's got lots of wickets this season at not very many and he's bowling very well.”

Harmison has taken 42 wickets in nine first-class matches this season at an average of 19.38, a tally that includes six wickets against the Australians in their final pre-Ashes warm-up match at Worcester.

Asked whether Harmison could translate these figures to international cricket, Cook said: “Well, he's just played against Australia and bowled pretty well then.”

Most importantly, Harmison has rediscovered the rhythm that is so important to his bowling.

As so often, he was some way from his best early in the season, but he has played enough cricket this summer for the cadence to return.

Anthony McGrath, the Yorkshire captain and former England batsman, felt the full force of this at Headingley, taking a painful blow on the hand before he was caught at slip.

“When he's in the rhythm he's in at the moment, he's really difficult to play,” McGrath said. “His rhythm is nothing to do with his fitness, he just needs to bowl and bowl and he's done that.

“You see the fields that are set and there aren't many people in front of square and he doesn't pitch many balls up, so it's difficult to score from.”

England's bowlers laboured on a pitch of gentle pace at Cardiff, but McGrath believes that Harmison, in his present form, could have made a real difference.

“He's an attacking option because of his pace and bounce and there aren't many bowlers in the world who have those attributes,” McGrath said.

“He brings something different and on a flat pitch like Cardiff, when the ball's not swinging or seaming around, he could extract things that other people can't.”

Harmison, 30, has taken 221 wickets in 61 Tests, the last of which was the third against West Indies in Antigua in February. He was dropped after that game, continuing his on-off relationship with the England selectors in recent times.

Geoff Miller, the national selector, said last week that “there might be a surface later in the series that requires his type of bowler”.

The hope was clearly that Harmison could be held in reserve, but after the bowlers' poor performance in the first Test the temptation must be strong to recall him if the pitch at Lord's is quicker than Cardiff.

Graham Ford, the former South Africa coach and now director of cricket at Kent, is in no doubt about Harmison's value to a side when he is fully fit and firing.

“When Harmison is bowling well, he walks into any Test side of mine and I would be disappointed if they [the selectors] don't grab hold of him now,” he said. “I know when he's not quite right he can be a bit wayward, but when he's in form you pop him straight back into your side because he gets good batsmen out. I think that's certainly a change they've got to look to make.”