The Club's worst fears were realised when a scan showed that Morkel had sustained a grade two hamstring injury during the recent LV County Championship match against Nottinghamshire.

Morkel pulled up during Friday's play complaining of a tightening in the right leg which was initially diagnosed as a potential hamstring problem or cramp.

He missed the rest of the Nottinghamshire match and also Bank Holiday Monday's Friends Provident Trophy win over Durham Dynamos as a precautionary measure. A scan on Wednesday however, has shown that the injury was more serious than first feared.

The estimated healing time for such a hamstring injury is anything between three and six weeks and as Morne was due to be replaced by Rana Naved in early June, at the latest, the club and player have decided that it is in the best interest of both parties for Morne to return to South Africa to rehabilitate ahead of South Africa's tour of England in the second half of the summer.

Morkel said: "I am really upset that an injury is forcing me to return home. Everyone at Yorkshire has made me very welcome and I was desperate to take some wickets and get Yorkshire off to the best possible start.

"I wish the club every success this season and look forward to seeing everyone again when I am back here for the Tests and One Day Internationals with South Africa. Hopefully my chance of playing county cricket for Yorkshire has not gone forever."

Martyn Moxon, director of professional cricket, said: "We are all sad to see Morne depart so soon after his arrival. He was fitting in well, provided our bowling attack with some variety as he is a genuinely quick bowler. We wish him all the best in his recovery.

"We have a strong squad and as Rana Naved will be unable to be registered as a Yorkshire player before May 19 there is now a chance for one of our other seamers to grab an unexpected 1st Team opportunity."

Stewart Regan, chief executive, said: "In the short time Morne has been with us he has become a popular figure at Headingley Carnegie. It is incredibly disappointing for him and us that he will play no further part in our season, but we look forward to welcoming him back to Yorkshire for July's Test Match at Headingley Carnegie and the August One Day International when he will be touring with South Africa."

Morkel will travel with the Yorkshire Carnegie squad to Old Trafford on Sunday. He will watch the Friends Provident Trophy Roses match, say his goodbyes and fly home to South Africa after the match has ended.