The 32 year-old Cronje has set up camp in Durban where he is training with the Sharks as part of their Currie Cup squad.
The creative flyhalf has enjoyed an extremely colourful career to date, having turned out for the Stormers, Western Province, Blue Bulls, Golden Lions, Sharks and Southern Kings in his native South Africa while, abroad, he has represented the Brumbies and Toyota Verblitz.
The Sharks will be missing a string of big names as the Lions tour gets underway next month and will thus be grateful for the cover Cronje is willing to provide. He last played for the Sharks in 2014-15.
Two other notable returnees to the Sharks squad are Cameron Wright and Khuta Mchunu.
The Currie Cup will kick off on the weekend of 18 June.