Costa was in high spirits during Thursday's (Friday AEST) training session at Cobham, playing a prank on his teammates by poking fun at himself and his well-known combustable temper.
The striker is seen hijacking the club's utility cart and taking it for a joyride, mowing down a row of witches hats.
Then, to the amusement of his Blues teammates, the Spaniard pretended to have a moment of rage by smashing up a number of hurdles laid out by the coaching staff.
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Not to be outdone Chelsea's arch-prankster David Luiz also got in on the action.
Not that Chelsea skipper John Terry found the Brazil defender's idea of a joke very amusing.
