Australia all-rounder Shane Watson's participation in the third and final Test against Sri Lanka, which gets underway in Sydney on 3 January, hangs in the balance after Thursday's calf injury.

Watson strain his left calf - the same muscle that ruled him out of two Tests against South Africa earlier this year - while bowling on day two of the second match in Melbourne.

The injury, however, did not prevent the right-handed Watson from scoring a fine 83 during more than four hours at the crease in a total of 440 for eight - and a lead of 284.

"He was able to get though the batting innings today and is likely to field on day three. Whether he bowls in the second innings will be determined closer to the bowling innings," said team physiotherapist Alex Kountouris.

"A decision on his availability for the Sydney Test will be made after the completion of the current match."