The north London side were the only team in the Premier League not to make any movements in the summer, and the Argentine hinted it could happen again in January.
"No, not disappointed. I know very well that January is always difficult," he said.
"In the same way, if you find some player, look what happened to different players that arrive in January last season.
"It takes time to understand and to perform, to fit with the team. Sometimes it's better not to sign if you don't find the right player."