Sri Lanka's Chanaka Welgedara walks off after injuring his hamstring.

Sri Lanka's Chanaka Welgedara walks off after injuring his hamstring. Photo: Sebastian Costanzo

SRI Lanka, beset by injuries, is likely to turn to one of its Big Bash League contingent for the final match of the Test series in Sydney. But odds are it won't be former Test star Lasith Malinga.

All-rounder Thisara Perera is instead the front-runner to be called up to the squad at the SCG, forcing a last-minute change of plans by his BBL franchise Brisbane Heat.

The tourists were effectively reduced to nine men on Thursday when their leading bowler, left-armer Chanaka Welegedara, left the ground before lunch nursing an injured hamstring.

The Lankans had already lost wicketkeeper Prasanna Jayawardene with a fractured thumb and have a second quick on the injured list, with Nuwan Kulasekara missing the Boxing Day Test due to fractured ribs.

Welegedara and Kulasekara have been all but ruled out of the third Test. Fast bowling fitness issues are certainly not exclusive to Australia.

Perera's contract with the Heat was due to expire at the end of Friday night's match against Sydney Thunder at ANZ Stadium but on Wednesday evening was extended until the conclusion of Brisbane's game next Thursday against Malinga's Melbourne Stars at the Gabba. That will be torn up if the 23-year-old, due to feature in the limited-overs series to follow the Sydney Test, is asked to join the national squad. A member of the team that made the World Twenty20 final in Colombo in October, Perera has played six Tests, the most recent in July.

Sri Lankan bowling coach Champaka Ramanayake said last week the visitors may try and persuade Malinga to come out of retirement from Tests if their pacemen did not fire in Melbourne.

Malinga played the last of his 30 Tests in August 2010, quitting the longer form to prolong his one-day and Twenty20 career. He has grabbed attention in the BBL, most notably with remarkable figures of 6-7 against Perth Scorchers. It is unlikely he can be convinced to come out of Test retirement for what will likely be a dead rubber.

Marvan Atapattu, Sri Lanka's batting coach, said the tourists hoped Jayawardene, hit by Mitchell Johnson on Wednesday, could bat in the second innings but would not keep. He is also in doubt for Sydney.

''The news from the physio is that Welegedara is very doubtful and, of course, Kulasekara has got a hairline fracture on one of his ribs,'' Atapattu said.