Both teams made one change each from the side that played the second match.
Pakistan dropped Salman Butt and brought in another left-handed opener Imran Farhat, while Sri Lanka brought in paceman Dhammika Prasad for Nuwan Kulasekara.
Pakistan lead the series 1-0 after winning the second match by four wickets. The first match of the series was abandoned due to rain.
Sri Lanka: Mahela Jayawardene (capt), Upul Tharanga, Kumar Sangakkara, Tillakaratne Dilshan, Russel Arnold, Chamara Kapugedera, Farveez Maharoof, Kaushal Lokuarachchi, Lasith Malinga, Muttiah Muralitharan, Dhammika Prasad.
Pakistan: Inzamam-ul Haq (capt), Younis Khan, Mohammad Yousuf, Abdul Razzaq, Shahid Afridi, Shoaib Malik, Kamran Akmal, Imran Farhat, Rana Naved-ul-Hasan, Mohammad Asif and Rao Ifthikar.
Umpires: Steve Davis (AUS) and Asoka de Silva (SRI), TV umpire: Peter Manuel (SRI)
Match Referee: Alan Hurst (AUS)