Sagan, the 2008 world junior XC champion, will race two MTB events - one in Austria and one in the Czech Republic - bedecked in Tinkoff colours and on-board a Specialized S-Works Epic.
“It’s going to be good fun returning to my roots, racing mountain bikes again and I look forward to seeing what shape I will be in at those races,” Sagan said.
“My victories at Gent-Wevelgem and Ronde van Vlaanderen take the pressure off, so I hope that I can go off-road and be able to compete at the front, like I do on the road.”
His Tinkoff team management are behind the move.
"Peter has shown this spring what a star he is on the road and with the public, so to have this opportunity to take this to mountain bike fans too will be really nice," Stefano Feltrin, Tinkoff General Manager said.
"It’s a good opportunity for Tinkoff to showcase its partners in another discipline and we have every confidence he will take the racing seriously and perform to his best."
Sagan is well known for his road bike handling skills developed after a strong off-road career.