Ledesma, who took over the top job ahead of the 2018 season, named a 29-man squad for a preseason trial against the Bulls and their opening Super Rugby clashes against the Stormers and Lions.
The former Wallabies scrum coach has named rookie propr Javier Diaz in the team, replacing Santiago Garcia Botta.
Flanker Pablo Matera will skipper the side, with Joaquin Tuculet and Tomas Lezana the vice-captains.
Ledesma said his first round of selections was the most difficult.