The chances of Watson leading Australia for the first time in a Test increased after Clarke skipped the nets at the Feroze Shah Kotla here Wednesday.
Clarke was clearly struggling with a recurring back pain during the Mohali Test which India won to take an unassailable 3-0 lead in the series.
Clarke did not train and spent his time chatting with head coach Mickey Arthur and selector Rod Marsh, though he did have a closer look at the wicket.
Watson appeared visibly happy and could barely wipe the smile off his face following the birth of his son Will.
It also appears that Watson has patched up with Cricket Australia's (CA) high-performance chief Pat Howard, who had called Watson as only "sometimes a team player". Howard moved around the ground with the phone glued to his ear.
An out-of-form Watson has been at the centre of a controversy after he was sidelined from the third Test in Mohali along with three others over a breach of team discipline last week.
Watson was angry and left for home to be with his wife Lee, who delivered baby boy Will last Thursday. Watson, who left India contemplating retirement, however, returned in time to be with the team for the fourth Test.
Teammate Ed Cowan said everything was fine with the team.
"In his own words, he has probably decided to come back with a full focus and we will accept him because he is such a great player and a good leader. He is a senior player around the group and it is important those kinds of players are on board because we need those guys for this team to be the best team in the world," said Cowan.
"Shane is more a lead-by-example kind of fellow in terms of how he prepares. He doesn't leave many stones unturned -- and the way he has performed across all formats -- that is an example in itself. He is a very different leader to Michael, but we're hoping Michael is fine for this Test. He's such a great batsman and we need his runs and his leadership," he added.