Hussey, who is currently part of the host broadcaster's commentary team, will join CSK tomorrow.
The 36-year-old has previously played for Kings XI Punjab and Kolkata Knight Riders. The right-hander had tweeted yesterday that he received some "amazing news" but did not mention about the signing.
"I've been lucky enough to be over here commentating on the IPL and got called in to replace him as part of the Chennai Super Kings," Hussey told sen.com.au today.
"I haven't actually picked up a cricket bat or anything so I think come tomorrow I'll fly into Delhi and face some balls in the nets," he added.
"I'm lucky enough to be joining a team that is actually flying at the moment," he said further.
Hussey's brother Michael, who is part of Mumbai Indians, said he had not heard from him about the CSK move.
Talking to the commentators during MI-Sunrisers Hyderabad game tonight, Michael Hussey said he had sent an SMS to his brother but had not received a reply.
CSK, who are at second place in the Points Table, will face Rajasthan Royals tomorrow in Ranchi.