Nathan Lyon is set to make his Specsavers County Championship debut against home side Derbyshire tomorrow – with Worcestershire assistant coach Matt Mason confident he will have a big impact on and off the pitch.

The Australian spinner, who has taken 247 wickets in 67 Tests, made his first appearance for the club in the Royal London One-Day Cup win at the 3aaa County Ground on Tuesday.

But he will now be available for a series of Championship matches as a replacement for John Hastings as well as being eligible for the One-Day Cup semi-final versus Yorkshire Vikings or Surrey at New Road on June 17.

Mason, who is also the County's bowling coach, said: "I think he will have a huge impact. He is obviously an international spinner and one of the best going.

"He has played 60-70 times for Australia in Test match so brings a wealth of experience.

"I think he will revel playing in different conditions. He has never played county cricket before although he has been in England before (with Australia).

"He will have to adapt quickly but he is quality.

"I think as well as his on the field performances he will bring the same energy we've had from John Hastings.

"They are both similar characters, quite boisterous, quite big drivers in the dressing room but I also think he will pass on some of his knowledge to our young spinners.

"George Rhodes, Ben Twohig and these guys will benefit from him being here."

Joe Clarke is included in the 12 strong squad after missing the One-Day Cup success with a hamstring injury.

Worcestershire have won their opening two matches in the four-day competition as they prepare to switch back from white ball cricket to the longer format.

Director Of Cricket Steve Rhodes said: "It is going to be interesting because we had a breather yesterday and we've probably got one practice before we start again in the four-day stuff.

"Hopefully we will be more ready than the opposition and going back to four-day cricket, is never easy after 20 over cricket or 50 over cricket.

"But hopefully we will be ready and attack that game in the same light as we always do and try and get ourselves in that winning position and ram it home."

Worcestershire (from)

Mitchell

D'Oliveira

Fell

Clarke

Kohler-Cadmore

Cox (w)

Barnard

Leach (c)

Tongue

Shantry

Lyon

Rhodes