Sheffield Wednesday have suffered an embarrassing gaffe after their loss in the Steel City derby over the weekend. Wednesday , still licking their wounds from the defeat, wanted to send an allocation of away tickets to Championship strugglers Oxford United - who travel to Hillsborough on April 12. However, the Owls didn't post the tickets to the Kassam Stadium to be sold, because they incorrectly addressed them to Oxford City - United’s non-league neighbours from four divisions below. City posted the tickets on social media, alongside a cheeky promo for £5 tickets for their clash with Warrington Town at their MGroup Stadium for an upcoming non-League day. In the cheeky post, The Hoops said: "A big thank you to @swfc for the delivery of 4,000 tickets for your game vs Oxford United. To the intern at the Hillsborough ticket office, don’t worry, we’ve all been there! "U’s fans, don’t panic. We’re delivering 3,997 of these to @OUFCOfficial after lunch..." "Send them back to Sheffield United," one fan joked. While one Blades fan responded: "I see that them in S6 have found their level of football, playing teams like Oxford City!" "Love this fab advertisement for non league," a third joked. And another added: "This is an absolute masterclass in marketing from Oxford City btw!" While a further fan said: "What are you doing with the other three?" It's a common mistake, according to Oxford City's press officer Andy Gate, who told The Sun : "We do get calls now and then for people who want to get tickets to Oxford United and get the wrong number. "And usually I'm quickly googling the Oxford United website to give them the number for the ticket office there. But we've had nothing like this, not at all. “With the risk of sounding like Mick from Gavin and Stacey, it's not the thing you expect when you come to work in the morning is it?” Wednesday have a clash with Cardiff over the weekend, while Oxford United are in desperate need of all three points when they face Middlesbrough.