Pakistan fast bowler Shoaib Akhtar has been ruled out of the second test against Sri Lanka starting on Thursday because of a shoulder injury.

"The doctors have advised me to rest for two weeks to recover from the problem," Shoaib said on Wednesday.

"I have acute pain in my right shoulder which is very stiff. I could have played by taking pain killer injections but it is risky and I have decided to take the rest."

The 29-year-old, who spearheaded the Pakistan attack in the first test in Faisalabad with eight wickets, joins fellow new ball partner Mohammad Sami on the injury list as Pakistan try to prevent Sri Lanka from completing a hat-trick of series wins in Pakistan.

Sri Lanka, who won the first test in Faisalabad by 201 runs, have won test series in Pakistan in 1995/96 and 1999/2000.

Shoaib has taken 133 test wickets in 33 matches.

Sami has been ruled out with a groin injury he suffered in the first test while Pakistan has already lost pace bowlers Shabbir Ahmed and Umar Gul to injuries before the series.

"We will go in with the back-up bowlers Rana Naved and Riaz Afridi," said captain Inzamam-ul-Haq.

Naved has played in one-day internationals only while 19-year-old Afridi is also uncapped.

"There is now pressure on us to level the series and every batsmen will have to score runs," Inzamam said.