Mendes has failed to impress at the Old Lady and has struggled to get into the first team.
“It was a mistake leaving Lyon to come to Juventus,” Tiago told Tuttosport.
“I thought that coming here would have been a step forward joining a big squad but it didn’t go the way I had hoped.
“If I could go back I wouldn’t have made this choice and in life you need to choose.”
Tiago believes the Bianconeri can get to the Champions League final in May next year.
“There are big players here and I want to take this side to the Champions League final,” added Tiago.
