Cricket Australia physiotherapist Alex Kountouris broke the news late Thursday night.
"Shane sustained a left calf injury while bowling on day one," Kountouris said.
"He was able to get though the batting innings today and is likely to field on day three (Friday).
"Whether he bowls in the second innings will be determined closer to the bowling innings.
"A decision on his availability for the New Year Test will be made after the completion of the current match."
Watson and captain Michael Clarke added 194 for Australia's fourth wicket on day two, the skipper made 106 and Watson fell in the very next over for 83.
Mitchell Johnson will resume on 73 on Friday, aiming to stretch the home side's lead beyond 300.
At 8-440 in their first innings, the Australians hold a 284-run lead.