Arsene Wenger joked that he was tempted to send in the drones to prepare for Arsenal's FA Cup quarter-final against Watford.
Arsenal's training base at London Colney neighbours the facilities used by their fellow Premier League side.
"Yes, all week [we have used drones]. Silent ones," he said ahead of Sunday's quarter-final match.
"No, we respect, and I think they do as well, the confidentiality of training. We didn't go over the fences. I was tempted to take a look there I didn't do that."
With Arsenal eight points adrift of Premier League leaders Leicester City and 2-0 down to Barcelona in their Champions League last-16 tie, Wenger was asked whether the FA Cup – which his side have won two years running – was their best chance of a trophy.
"I don't know [if it is our best chance]. I don't think like that," he added. "I haven't given up on the Premiership or the Champions League.
"In this job you take charge of the next minute, the next minute is the FA Cup. Is it our best chance of trophy? There's still a long way to go, but we have to show we can be consistent again."
