Chelsea have been thrown into confusion few days before their Europa league quarterfinal clash this month.
The Premier League giants were initially drawn to battle Slavia Prague at the last eight stage of the competition next week.
Meanwhile, the Blues shared a message on their website advertising the tickets for their matches against West Ham and "Sparta Prague".
SunSport however revealed that Sparta Prague aimed a hilarious jibe at the Stamford Bridge outfit on Twitter, while also taking a pop at their cross-city rivals in the process.
Sparta wrote: "Hi guys @ChelseaFC, we completely understand you are confused, since we are the most famous and most successful club from Prague. "But this time you play against Slavia, sorry..."
Coach Maurizio Sarri's men travel to the Czech Republic for the first-leg of their last-eight tie on Thursday April 11 - three days after taking on West Ham at Stamford Bridge.
Before then, Chelsea battle Brighton on Wednesday - with Maurizio Sarri set to hand Callum Hudson-Odoi a rare start.
While Ruben Loftus-Cheek is likely to fit into midfield for the clash against the Seagulls, as Sarri plumps for a youthful XI.
Legit.ng: Chelsea manager Maurizio Sarri has admitted feeling all alone at the club as he seems not to have found a lasting solution to his team’s inconsistent form this season.
The Blues are chasing their first win in three games when they face relegation threatened Cardiff on Sunday, March 31.
Ahead of the game, Sarri knows he is all alone should his team suffer yet another defeat after going down 2-0 against Everton in their last Premier League tie.