If there is one superstar that has been the biggest surprise at the end of 2017, it has to be SmackDown Live's Rusev, as his Rusev Day gimmick is going down really well with the WWE Universe.

Since pairing with Aiden English, The Bulgarian Brute has done nothing but reached new heights in his WWE career, further than where he was at during his time as United States Champion when he was feuding with John Cena.

While Rusev and English are yet to have much success as a tag team, they're having great success in getting the Rusev Day gimmick over with the WWE Universe, and this fact has had a knock-on effect in t-shirt sales.

According to NoDQ, out of all products and not just shirts, the Happy Rusev Day t-shirt is currently the best selling item on WWEShop.com. It also has "back order/pre-order" status when you attempt to order a shirt on the site, and the shirts have also reportedly been selling very well at live events. 

Although it's possible that WWE underestimated the demand for the shirts, the fact they're selling out is a positive sign that the phrase has made a connection with the fans and that the gimmick is getting over with the WWE Universe. WWE needs to capitalize on this pronto.

Below are the top five selling t-shirts on WWEShop.com right now. As you can see, the Happy Rusev Day t-shirt is outperforming The Shield, which is very surprising to see considering The Shield's popularity amongst WWE fans.

  • Rusev "Happy Rusev Day" Authentic T-Shirt 
  • The Shield "Shield United" Authentic T-Shirt 
  • The Usos "Down Since Day One Ish" Authentic T-Shirt 
  • nWo Retro T-Shirt 
  • AJ Styles "Untouchable" Authentic T-Shirt

While WWE is yet to reveal their future plans for Rusev, English will be participating in the United States Championship tournament against Xavier Woods next week on SmackDown. If he wins this match, he will go on to face Jinder Mahal.

If he beats Mahal, he will face either Booby Roode, Zack Ryder, or Mojo Rawley at the Royal Rumble, depending on how their matches unfold on their side of the tournament bracket.

Considering the popularity of Rusev Day, you could definitely see WWE pulling some moves to allow English to give up his spot in the tournament to Rusev. The Bulgarian Brute would then beat Woods, as well as Mahal to advance to the final in order to capitalize on the hype of Rusev Day.