Lehmann is returning ahead of the Australian team for intensive treatment on his torn hamstring ahead of the beginning of court proceedings on November 15 in Melbourne that will force him to relive some bad memories.
He was by Hookes's side the night he died outside a Melbourne pub last January and will be the first witness to give evidence at the trial of security guard Zdravko Micevic, 21, who has previously indicated he will plead not guilty to fatally attacking Hookes.
Three days later Australia are due to play New Zealand in the first of two Tests in Brisbane.
"I'm first up so I can get to Brisbane," Lehmann told Australian Associated Press in Mumbai on Tuesday ahead of the fourth and final Test against India.
"I think about it (giving evidence), but it doesn't play on my mind. It's more of a case that it's going to be a pretty bad day, but I've had plenty of those in the last while. You've got to do it and it's there for a reason. The system will make whatever decision it makes."
Lehmann's torn right hamstring ruled him out of Wednesday's fourth Test and despite the success of middle-order players Michael Clarke and Simon Katich, the 34-year said: "If I was a betting man I would say I'm a pretty good price to start (against New Zealand).
"But then again, things can change. The main thing for me is making sure I'm fit and ready to go for that game and then whatever happens there happens. I'm confident I'm going to play and ready for it -- but I just can't afford another setback."
Lehmann has received positive indications from the selectors about his chances of being reinstated.
"I've spoken to certain people and its a case of, 'Get ready for Brisbane,' said Lehmann.
"That doesn't give me any guarantees, of course, but it's nice to know they are behind me."