Australia all-rounder Shane Watson could be in line to make his Test captaincy debut in the second Test against Sri Lanka, if skipper Michael Clarke's hamstring injury is serious enough to rule him out.

Clarke limped off while batting in Hobart on Monday, having made 57, and was sent for scans. Coach Mickey Arthur conceded that while the results were unknown, they would be looking at who could take over the armband if required.

The South African said of Watson's chance: "It is a distinct possibility, it would be a really good challenge for Shane. We'll learn a lot about Shane and his leadership ability, I'm confident he will come through it very well.

"If it does materialise, it will be a really good opportunity for him."

Arthur also addressed who might bat in Clarke's place, should the prolific batsman not recover in time. Wicketkeeper Brad Haddin's name was mentioned, as well as Rob Quiney, who was not picked for the first Test after making his debut against South Africa.

Arthur continued: "That batter, whoever it is, would have to be part of our extended squad. There are possibilities. Haddin's one of them, Quiney's one of them and certainly Usman Khawaja's very much in the frame. Alex Doolan has played well also."