Sri Lanka's leading pace bowler Chaminda Vaas has been ruled out of the first Test against South Africa, starting on Thursday, with a hamstring injury.
The 32-year-old left armer has not fully recovered from the injury which he sustained during the recent tour of England.
"Chaminda started bowling three days ago and he is bowling really well but we want to give him adequate time to recover properly," captain Mahela Jayawardene told reporters.
"It is a huge blow for us considering the experience he possesses with the ball and his batting during the recent England tour, but we have to manage him properly as we have lots of cricket coming up."
With Vaas absent, Sri Lanka are poised to play Dilhara Fernando, Lasith Malinga and Farveez Maharoof in a three-man pace attack supported by spinner Muttiah Muralitharan.
Sri Lanka have reduced their 14-man squad to 12 after omitting Vaas and opener Michael Vandort.
Wicketkeeper Prasanna Jayawardene is expected to play to allow Kumar Sangakkara to concentrate on his batting.
"We feel Sanga will benefit a lot if Prasanna keeps wickets so that he can concentrate on his batting, especially in the longer version of the game," said Jayawardene.
"It's a demanding job and he was finding it a bit difficult because of the amount of matches we are playing."
Sri Lanka squad: Mahela Jayawardene (captain), Upul Tharanga, Sanath Jayasuriya, Kumar Sangakkara, Tillakaratne Dilshan, Chamara Kapugedera, Prasanna Jayawardene, Farveez Maharoof, Lasith Malinga, Dilhara Fernando, Muttiah Muralitharan, Malinga Bandara.