Shoaib took 4-36 on his Test return in Port Elizabeth

Shoaib, 31, suffered a hamstring injury during South Africa's first innings in the second Test when he took 4-36. He could not bowl in the second innings.

It marred his first Test appearance for 11 months after injury and the lifting of a drugs ban, and is likely to rule him out of the one-day series as well.

Gul will also miss the one-dayers in February with an ankle complaint.

Shabbir Ahmed is flying to South Africa as fast-bowling cover and is likely to stay on for the one-day series.

After serving a one-year ban for having an illegal bowling action, Shabbir could be in contention for a place immediately.

Saleem Altaf, Pakistan's director of cricket operations, said: "Shoaib has been ruled out of action for at least two weeks with a grade one hamstring tear and has also developed fluid in his knee.

"Both he and Umar Gul will be examined by a medical commission when they return home."

Seam bowler Shabbir Ahmed and all-rounder Abdul Razzaq are to be sent to South Africa as a result of the injuries.

Shoaib, meanwhile, is also set to face an internal disciplinary hearing after TV cameras showed him in an altercation with coach Bob Woolmer in the dressing room before the start of play on Saturday.

"I have talked with [team manager] Talat Ali on this particular incident," said Altaf.

"He has assured the board that he would conduct an inquiry and then take action, if required.