Sydney Thunder chief executive Nick Cummins confirmed the success-starved franchise has commenced preliminary discussions with Jacques Kallis's management to try and lure the champion South African all-rounder for next season's T20 Big Bash League.

Kallis, 38, recently retired from Test cricket with a batting average of 55.37 and 32.65 with the ball. He was identified by the Thunder, who finished with the wooden spoon in each of the three Big Bash League seasons, as the calibre of player needed to help propel the team among the competition's heavyweights.

"We've been talking to his management, but I know a few teams are," Cummins said on Tuesday.

Cummins said it was impossible to do anything more than talk to Kallis's manager until the middle of May because Cricket Australia had an embargo on Big Bash League teams signing players until a yet-to-be-confirmed date in May.

"We can't formalise agreements with anyone until then," Cummins said. "We hope to put together an inducement that would get him across the line because he'd be a great addition for us.