Zambrano, 32, last pitched in the major leagues for the Miami Marlins in 2012. He's a free agent and throwing in Venezuela for Navegantes del Magallanes. He's 0-1 with a 3.20 ERA in four starts.
"He is most definitely interested in continuing his career," Praver said on Monday from the GM meetings.
Zambrano pitched for the Cubs from 2001-2011, winning 125 games. A major league source says the Cubs have no interest in bringing Zambrano back to Chicago.
Zambrano was with the Philadelphia Phillies organization last season but his comeback stalled with a minor shoulder injury that ended his season prematurely. Praver says Zambrano is now healthy.
Zambrano's embattled Cubs career came to an end when the team suspended him for the final six weeks of the 2011 season. He was subsequently traded to the Marlins.
Asked if Zambrano would be open to attending a Cubs Convention -- if invited -- after retirement, Praver said: "I have no doubt that he would come. Carlos speaks very fondly of Chicago and Cubs fans."