Borriello was one of the long-listed candidates for the trip to South Africa, but was eventually cut from the final 23-man squad.
“I am not complaining about the choices made, as I was prepared to be dropped, but I wasn’t convinced by his methods,” Borriello told the Gazzetta dello Sport.
“You don’t leave five players hanging there for a week without giving them an explanation.
“It’s especially galling, as afterwards it became clear that the decisions had already been made beforehand. There was no great difference in quality between those who went to South Africa and who stayed behind.
“The problem was the group dynamic. All good lads, but they were missing leaders. We felt the absence of charismatic players like Marco Materazzi, Massimo Ambrosini, Francesco Totti or Alessandro Del Piero.
“I say all this without even touching upon the Antonio Cassano issue.”