A prankster keeps creeping into the changing room at their training ground to cut up their designer pants.
That's a turn-up for some of the players - who at times have had trouble keeping their pants ON.
The mystery assailant strikes up to twice a week while the Blues train at Cobham, Surrey.
His cheeky attacks have threatened the players' ball control and could easily lead to some ugly tackle being seen in the penalty box.
England star Frank Lampard said: "It's gone on for about a year. We get in to find the bum cheeks cut out of our underpants.
"It has to be one of the players. They are the only ones with access. You might get two hits in a week, then he won't attack for a month or so."
Lamps, 32, added: "I've a good idea who it is but wouldn't dream of making accusations until I have proof.
"I hope it's soon - it's costing a fortune in designer underwear!"
A club insider said: "It was a bit of a laugh but now the lads are a bit cheesed off. "There's hardly any holes in our defence - so it's a shame the same can't be said of our underpants."
It's not the first time the boys have experienced trouble in the underwear department. Ashley Cole got dumped by wife Cheryl this year after sending photos of himself in his Y-fronts to a topless model.
hardly any holes in their defence? lol. Alright, let wait for their first real test in september with man city. Let's see the likes of terry run their lungs out.
Not no holes in the defence la...lol the article just claimed that because of the 6 nils wins...
well check out what the "club insider" said....haha