Football clubs in England are going to be extra careful from now on following ‘Spygate’.Leeds United boss Marcelo Bielsa, busted after being caught spying on Derby County’s training session ahead of their match on January 11, has opened up a can of worms.The Argentinian admitted to spying on every opponent that Leeds have faced this season in a remarkable press conference on Wednesday."Many condemning the behaviour, saying that it was not ethical, it was not moral,” Bielsa said to the assembled media, per Sky Sports. “I observed all rivals we played against. We watched all the training sessions before we played them."What I have done is not illegal. We can discuss it, it's not seen as a good thing, but it's not a violation of the law.”It’s since emerged that spying in football is more common than many would think.Pep Guardiola admitted on Friday that opposing staff members would watch his Bayern Munich sessions from a nearby mountain.

Crouch remembers Leeds 3-1 Stoke in August

Yet Bielsa’s admission has left Peter Crouch stunned.

Crouch, who is plying his trade with Stoke City, now looks back on the Potters’ 3-1 defeat to Leeds in August differently after finding out that Bielsa had sent spies to watch them in training in the days leading up to the match.

“The story with Leeds boss Marcelo Bielsa has taken things up to a whole new level,” Crouch wrote in his column for the Daily Mail.

“Even now, as I think about what he has admitted to this week, I can't quite believe it.

“We play Leeds at the Bet365 Stadium on Saturday. We were the first team to play them this season. They beat us 3-1 on August 5 and when I look back at that match in light of his revelations - they overran us in the first 20 minutes - it makes me wonder what they knew in advance. 

“Our Clayton Woods training ground is in a rural area that dog walkers regularly use.

“You can see the pitches and we often have fans watching so I can only assume some of Bielsa's staff joined them last summer, given what he said on Wednesday.”

Watch: Leeds 3-1 Stoke highlights

It must be a weird feeling for the other 23 clubs in the Championship to know that their training sessions have been observed by Bielsa’s team.

But Crouch doesn’t believe that it’s the sole reason for Leeds’ success this season.

“Leeds are not top of the table because they have been watching other teams train,” he added.

“They are an impressive young side, full of energy and desire - and they have been well drilled by one of the great modern coaches.

“Spying won't get them promoted. Bielsa will.”