Federer's new shoes & Sharapova's new sweets

Fourhand is the Daily Spin's occasional roundup of various hits and misses on tour.

PRAYERS KNEEDED  Roger Federer bowed out of the Australian Open semifinals against Novak Djokovic, but chances are he won't be bowing anytime soon in light of a surprise (to the tennis world) knee surgery. May his leg feel better in his new shoe in collaboration with NikeLab, the Tiempo Vetta. Federer, at times a tweeting fiend, has tweeted just once since beginning his Aussie Open campaign, telling the story of his surgery and expected recovery via (what else?) emojis, noting the heartbreak, pain and prayers involved in such a procedure.

Related: Say a prayer for Kimiko Date-Krumm as well. The 45-year-old Ironwoman of Tennis also has a meniscus problem in her knee and will undergo surgery, vowing to return to the WTA Tour.

THE TENNIS LAB  For all you innovation lovers, Carl Bialik's FiveThirtyEight read, "The Tennis Court Is A Laboratory For Innovation," is a must-see. "The sport's very format lends itself to invention and calculated risk-taking." Experiments and odds and stats, oh my!

THIS IS HAPPENING  Sugarpova Premium Chocolates are set to hit select stores in May. Their namesake owner started her sweets-turned-lifestyle brand in 2012 and hasn't looked back, partnering with Polish chocolate makers Barion Chocolates on the new line. And she may have traveled the world to find that best partner, but of late, Maria Sharapova has taken to the streets of Moscow with her main funny pal, Chelsea Handler.

'X' MARKS THE BULL  Perhaps lost in the shuffle at this year's Aussie Open, as was the man himself, Rafael Nadal and Kia linked up to promote the new X-Men flick alongside Tennis Australia and 20th Century Fox. Nadal was involved in a similar promo at the time of the 2015 major Down Under, and no doubt wishes for some X-powers right about now:

Follow Jon on Twitter @jonscott9.